diff --git a/src/ast.ts b/src/ast.ts
index da2271ef3d..38c1e5e8e4 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -49,6 +49,7 @@ export const enum NodeKind {
   Source,
 
   // types
+  ResolvedType,
   NamedType,
   FunctionType,
   TypeName,
@@ -168,6 +169,10 @@ export abstract class Node {
     return new NamedTypeNode(Node.createSimpleTypeName("", range), null, false, range);
   }
 
+  static createResolvedType(type: Type): ResolvedType {
+    return new ResolvedType(type);
+  }
+
   static createTypeParameter(
     name: IdentifierExpression,
     extendsType: NamedTypeNode | null,
@@ -863,6 +868,8 @@ export abstract class TypeNode extends Node {
       if (functionTypeNode.returnType.hasGenericComponent(typeParameterNodes)) return true;
       let explicitThisType = functionTypeNode.explicitThisType;
       if (explicitThisType && explicitThisType.hasGenericComponent(typeParameterNodes)) return true;
+    } else if (this.kind == NodeKind.ResolvedType) {
+      return false;
     } else {
       assert(false);
     }
@@ -870,6 +877,15 @@ export abstract class TypeNode extends Node {
   }
 }
 
+/** Represents a resolved type. Will be generated when  */
+export class ResolvedType extends TypeNode {
+  constructor(
+    public type: Type
+  ) {
+    super(NodeKind.ResolvedType, false, Source.native.range);
+  }
+}
+
 /** Represents a type name. */
 export class TypeName extends Node {
   constructor(
diff --git a/src/parser.ts b/src/parser.ts
index 58050e837e..56bb4a6571 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -2379,11 +2379,6 @@ export class Parser extends DiagnosticEmitter {
       if (tn.skip(Token.Colon)) {
         type = this.parseType(tn);
         if (!type) return null;
-      } else {
-        this.error(
-          DiagnosticCode.Type_expected,
-          tn.range()
-        ); // recoverable
       }
       let initializer: Expression | null = null;
       if (tn.skip(Token.Equals)) {
diff --git a/src/resolver.ts b/src/resolver.ts
index d6177806bd..a5a33af575 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -76,7 +76,8 @@ import {
   NewExpression,
   ArrayLiteralExpression,
   ArrowKind,
-  ExpressionStatement
+  ExpressionStatement,
+  ResolvedType
 } from "./ast";
 
 import {
@@ -159,6 +160,9 @@ export class Resolver extends DiagnosticEmitter {
     node.currentlyResolving = true;
     let resolved: Type | null = null;
     switch (node.kind) {
+      case NodeKind.ResolvedType:
+        resolved = (<ResolvedType>node).type;
+        break;
       case NodeKind.NamedType: {
         resolved = this.resolveNamedType(
           <NamedTypeNode>node,
@@ -3658,6 +3662,23 @@ export class Resolver extends DiagnosticEmitter {
       prototype.parent // same level as prototype
     );
     let getterPrototype = prototype.getterPrototype;
+    let setterPrototype = prototype.setterPrototype;
+
+    let initializerNode = prototype.initializerNode;
+    if (initializerNode != null && prototype.typeNode == null) {
+      let initialzerType = this.resolveExpression(initializerNode, instance.file.startFunction.flow);
+      if (initialzerType) {
+        if (getterPrototype) {
+          assert(isTypeOmitted(getterPrototype.functionTypeNode.returnType));
+          getterPrototype.functionTypeNode.returnType = Node.createResolvedType(initialzerType);
+        }
+        if (setterPrototype) {
+          assert(isTypeOmitted(setterPrototype.functionTypeNode.parameters[0].type));
+          setterPrototype.functionTypeNode.parameters[0].type = Node.createResolvedType(initialzerType);
+        }
+      }
+    }
+
     if (getterPrototype) {
       let getterInstance = this.resolveFunction(
         getterPrototype,
@@ -3670,7 +3691,6 @@ export class Resolver extends DiagnosticEmitter {
         instance.setType(getterInstance.signature.returnType);
       }
     }
-    let setterPrototype = prototype.setterPrototype;
     if (setterPrototype) {
       let setterInstance = this.resolveFunction(
         setterPrototype,
diff --git a/tests/compiler/class.debug.wat b/tests/compiler/class.debug.wat
index e8f373491e..53324bef57 100644
--- a/tests/compiler/class.debug.wat
+++ b/tests/compiler/class.debug.wat
@@ -2,17 +2,21 @@
  (type $0 (func (param i32 i32)))
  (type $1 (func (param i32) (result i32)))
  (type $2 (func (param i32)))
- (type $3 (func))
- (type $4 (func (param i32 i32) (result i32)))
+ (type $3 (func (param i32 i32) (result i32)))
+ (type $4 (func))
  (type $5 (func (param i32 i32 i32)))
  (type $6 (func (param f32 f32) (result f32)))
- (type $7 (func (param i32 i32 i32) (result i32)))
- (type $8 (func (param i32 f32 f32) (result f32)))
- (type $9 (func (param i32 i32 i32 i32)))
- (type $10 (func (param i32 i32 i64) (result i32)))
- (type $11 (func (result i32)))
+ (type $7 (func (param i32 i32 i32 i32)))
+ (type $8 (func (param i32 i32 i64) (result i32)))
+ (type $9 (func (result i32)))
+ (type $10 (func (param i32 f32)))
+ (type $11 (func (param i32 i32 i32 i32 i32) (result i32)))
+ (type $12 (func (param i32) (result f32)))
+ (type $13 (func (param i32 i32 i32) (result i32)))
+ (type $14 (func (param i32 f32 f32) (result f32)))
  (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
  (global $class/Animal.ONE (mut i32) (i32.const 1))
+ (global $class/outsideF32 (mut f32) (f32.const 1.2000000476837158))
  (global $~lib/rt/itcms/total (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/threshold (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/state (mut i32) (i32.const 0))
@@ -27,11 +31,13 @@
  (global $~lib/rt/itcms/fromSpace (mut i32) (i32.const 0))
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
  (global $~lib/native/ASC_LOW_MEMORY_LIMIT i32 (i32.const 0))
+ (global $class/memberTypeInfer (mut i32) (i32.const 0))
+ (global $~lib/native/ASC_SHRINK_LEVEL i32 (i32.const 0))
  (global $~lib/native/ASC_RUNTIME i32 (i32.const 2))
- (global $~lib/rt/__rtti_base i32 (i32.const 512))
- (global $~lib/memory/__data_end i32 (i32.const 544))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33312))
- (global $~lib/memory/__heap_base i32 (i32.const 33312))
+ (global $~lib/rt/__rtti_base i32 (i32.const 688))
+ (global $~lib/memory/__data_end i32 (i32.const 724))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33492))
+ (global $~lib/memory/__heap_base i32 (i32.const 33492))
  (memory $0 1)
  (data $0 (i32.const 12) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e\00\00\00\00\00")
  (data $1 (i32.const 76) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00 \00\00\00~\00l\00i\00b\00/\00r\00t\00/\00i\00t\00c\00m\00s\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00")
@@ -41,9 +47,14 @@
  (data $5 (i32.const 268) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s\00\00\00\00\00\00\00\00\00")
  (data $6 (i32.const 320) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data $7 (i32.const 348) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
- (data $8 (i32.const 412) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1c\00\00\00I\00n\00v\00a\00l\00i\00d\00 \00l\00e\00n\00g\00t\00h\00")
- (data $9 (i32.const 460) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1a\00\00\00~\00l\00i\00b\00/\00a\00r\00r\00a\00y\00.\00t\00s\00\00\00")
- (data $10 (i32.const 512) "\07\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02\t\00\00")
+ (data $8 (i32.const 412) "\1c\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\06\00\00\00h\00h\00h\00\00\00\00\00\00\00")
+ (data $9 (i32.const 444) "\1c\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\06\00\00\00i\003\002\00\00\00\00\00\00\00")
+ (data $10 (i32.const 476) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\10\00\00\00c\00l\00a\00s\00s\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00")
+ (data $11 (i32.const 524) "\1c\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\06\00\00\00f\003\002\00\00\00\00\00\00\00")
+ (data $12 (i32.const 556) "\1c\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\0c\00\00\00S\00t\00r\00i\00n\00g\00")
+ (data $13 (i32.const 588) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1c\00\00\00I\00n\00v\00a\00l\00i\00d\00 \00l\00e\00n\00g\00t\00h\00")
+ (data $14 (i32.const 636) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1a\00\00\00~\00l\00i\00b\00/\00a\00r\00r\00a\00y\00.\00t\00s\00\00\00")
+ (data $15 (i32.const 688) "\08\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\02\t\00\00")
  (table $0 1 1 funcref)
  (elem $0 (i32.const 1))
  (export "testGenericInitializer" (func $class/testGenericInitializer))
@@ -67,66 +78,6 @@
   f32.add
   return
  )
- (func $start:class
-  i32.const 4
-  i32.const 4
-  i32.eq
-  drop
-  global.get $class/Animal.ONE
-  drop
-  i32.const 1
-  i32.const 2
-  call $class/Animal.add
-  drop
-  f32.const 1
-  f32.const 2
-  call $class/Animal.sub<f32>
-  drop
- )
- (func $class/Animal<f64>#instanceAdd (param $this i32) (param $a i32) (param $b i32) (result i32)
-  local.get $a
-  local.get $b
-  i32.add
-  global.get $class/Animal.ONE
-  i32.add
-  return
- )
- (func $class/Animal<f64>#instanceSub<f32> (param $this i32) (param $a f32) (param $b f32) (result f32)
-  local.get $a
-  local.get $b
-  f32.sub
-  global.get $class/Animal.ONE
-  f32.convert_i32_s
-  f32.add
-  return
- )
- (func $class/Animal<f64>#get:one (param $this i32) (result i32)
-  local.get $this
-  i32.load
- )
- (func $class/Animal<f64>#get:two (param $this i32) (result i32)
-  local.get $this
-  i32.load16_s offset=4
- )
- (func $class/Animal<f64>#get:three (param $this i32) (result i32)
-  local.get $this
-  i32.load8_s offset=6
- )
- (func $class/Animal<f64>#set:one (param $this i32) (param $one i32)
-  local.get $this
-  local.get $one
-  i32.store
- )
- (func $class/Animal<f64>#set:two (param $this i32) (param $two i32)
-  local.get $this
-  local.get $two
-  i32.store16 offset=4
- )
- (func $class/Animal<f64>#set:three (param $this i32) (param $three i32)
-  local.get $this
-  local.get $three
-  i32.store8 offset=6
- )
  (func $~lib/rt/itcms/Object#set:nextWithColor (param $this i32) (param $nextWithColor i32)
   local.get $this
   local.get $nextWithColor
@@ -2327,6 +2278,16 @@
   local.get $ptr
   return
  )
+ (func $class/MemberTypeInfer#set:a (param $this i32) (param $a i32)
+  local.get $this
+  local.get $a
+  i32.store
+ )
+ (func $class/MemberTypeInfer#set:b (param $this i32) (param $b f32)
+  local.get $this
+  local.get $b
+  f32.store offset=4
+ )
  (func $~lib/rt/itcms/__link (param $parentPtr i32) (param $childPtr i32) (param $expectMultiple i32)
   (local $child i32)
   (local $parent i32)
@@ -2395,6 +2356,188 @@
    end
   end
  )
+ (func $class/MemberTypeInfer#set:c (param $this i32) (param $c i32)
+  local.get $this
+  local.get $c
+  i32.store offset=8
+  local.get $this
+  local.get $c
+  i32.const 0
+  call $~lib/rt/itcms/__link
+ )
+ (func $class/MemberTypeInfer#get:a (param $this i32) (result i32)
+  local.get $this
+  i32.load
+ )
+ (func $~lib/rt/common/OBJECT#get:rtSize (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=16
+ )
+ (func $~lib/string/String#get:length (param $this i32) (result i32)
+  local.get $this
+  i32.const 20
+  i32.sub
+  call $~lib/rt/common/OBJECT#get:rtSize
+  i32.const 1
+  i32.shr_u
+  return
+ )
+ (func $~lib/util/string/compareImpl (param $str1 i32) (param $index1 i32) (param $str2 i32) (param $index2 i32) (param $len i32) (result i32)
+  (local $ptr1 i32)
+  (local $ptr2 i32)
+  (local $7 i32)
+  (local $a i32)
+  (local $b i32)
+  local.get $str1
+  local.get $index1
+  i32.const 1
+  i32.shl
+  i32.add
+  local.set $ptr1
+  local.get $str2
+  local.get $index2
+  i32.const 1
+  i32.shl
+  i32.add
+  local.set $ptr2
+  i32.const 0
+  i32.const 2
+  i32.lt_s
+  drop
+  local.get $len
+  i32.const 4
+  i32.ge_u
+  if (result i32)
+   local.get $ptr1
+   i32.const 7
+   i32.and
+   local.get $ptr2
+   i32.const 7
+   i32.and
+   i32.or
+   i32.eqz
+  else
+   i32.const 0
+  end
+  if
+   block $do-break|0
+    loop $do-loop|0
+     local.get $ptr1
+     i64.load
+     local.get $ptr2
+     i64.load
+     i64.ne
+     if
+      br $do-break|0
+     end
+     local.get $ptr1
+     i32.const 8
+     i32.add
+     local.set $ptr1
+     local.get $ptr2
+     i32.const 8
+     i32.add
+     local.set $ptr2
+     local.get $len
+     i32.const 4
+     i32.sub
+     local.set $len
+     local.get $len
+     i32.const 4
+     i32.ge_u
+     br_if $do-loop|0
+    end
+   end
+  end
+  loop $while-continue|1
+   local.get $len
+   local.tee $7
+   i32.const 1
+   i32.sub
+   local.set $len
+   local.get $7
+   if
+    local.get $ptr1
+    i32.load16_u
+    local.set $a
+    local.get $ptr2
+    i32.load16_u
+    local.set $b
+    local.get $a
+    local.get $b
+    i32.ne
+    if
+     local.get $a
+     local.get $b
+     i32.sub
+     return
+    end
+    local.get $ptr1
+    i32.const 2
+    i32.add
+    local.set $ptr1
+    local.get $ptr2
+    i32.const 2
+    i32.add
+    local.set $ptr2
+    br $while-continue|1
+   end
+  end
+  i32.const 0
+  return
+ )
+ (func $class/MemberTypeInfer#get:b (param $this i32) (result f32)
+  local.get $this
+  f32.load offset=4
+ )
+ (func $class/MemberTypeInfer#get:c (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=8
+ )
+ (func $class/Animal<f64>#instanceAdd (param $this i32) (param $a i32) (param $b i32) (result i32)
+  local.get $a
+  local.get $b
+  i32.add
+  global.get $class/Animal.ONE
+  i32.add
+  return
+ )
+ (func $class/Animal<f64>#instanceSub<f32> (param $this i32) (param $a f32) (param $b f32) (result f32)
+  local.get $a
+  local.get $b
+  f32.sub
+  global.get $class/Animal.ONE
+  f32.convert_i32_s
+  f32.add
+  return
+ )
+ (func $class/Animal<f64>#get:one (param $this i32) (result i32)
+  local.get $this
+  i32.load
+ )
+ (func $class/Animal<f64>#get:two (param $this i32) (result i32)
+  local.get $this
+  i32.load16_s offset=4
+ )
+ (func $class/Animal<f64>#get:three (param $this i32) (result i32)
+  local.get $this
+  i32.load8_s offset=6
+ )
+ (func $class/Animal<f64>#set:one (param $this i32) (param $one i32)
+  local.get $this
+  local.get $one
+  i32.store
+ )
+ (func $class/Animal<f64>#set:two (param $this i32) (param $two i32)
+  local.get $this
+  local.get $two
+  i32.store16 offset=4
+ )
+ (func $class/Animal<f64>#set:three (param $this i32) (param $three i32)
+  local.get $this
+  local.get $three
+  i32.store8 offset=6
+ )
  (func $~lib/array/Array<i32>#set:buffer (param $this i32) (param $buffer i32)
   local.get $this
   local.get $buffer
@@ -2435,10 +2578,17 @@
  )
  (func $~lib/rt/__visit_globals (param $0 i32)
   (local $1 i32)
+  global.get $class/memberTypeInfer
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
   i32.const 224
   local.get $0
   call $~lib/rt/itcms/__visit
-  i32.const 432
+  i32.const 608
   local.get $0
   call $~lib/rt/itcms/__visit
   i32.const 32
@@ -2461,6 +2611,20 @@
  )
  (func $~lib/object/Object~visit (param $0 i32) (param $1 i32)
  )
+ (func $class/MemberTypeInfer~visit (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  local.get $0
+  local.get $1
+  call $~lib/object/Object~visit
+  local.get $0
+  i32.load offset=8
+  local.tee $2
+  if
+   local.get $2
+   local.get $1
+   call $~lib/rt/itcms/__visit
+  end
+ )
  (func $class/GenericInitializer<i32>~visit (param $0 i32) (param $1 i32)
   (local $2 i32)
   local.get $0
@@ -2491,28 +2655,34 @@
   block $invalid
    block $~lib/array/Array<i32>
     block $class/GenericInitializer<i32>
-     block $class/Animal<f64>
-      block $~lib/arraybuffer/ArrayBufferView
-       block $~lib/string/String
-        block $~lib/arraybuffer/ArrayBuffer
-         block $~lib/object/Object
-          local.get $0
-          i32.const 8
-          i32.sub
-          i32.load
-          br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $class/Animal<f64> $class/GenericInitializer<i32> $~lib/array/Array<i32> $invalid
+     block $class/MemberTypeInfer
+      block $class/Animal<f64>
+       block $~lib/arraybuffer/ArrayBufferView
+        block $~lib/string/String
+         block $~lib/arraybuffer/ArrayBuffer
+          block $~lib/object/Object
+           local.get $0
+           i32.const 8
+           i32.sub
+           i32.load
+           br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $class/Animal<f64> $class/MemberTypeInfer $class/GenericInitializer<i32> $~lib/array/Array<i32> $invalid
+          end
+          return
          end
          return
         end
         return
        end
+       local.get $0
+       local.get $1
+       call $~lib/arraybuffer/ArrayBufferView~visit
        return
       end
-      local.get $0
-      local.get $1
-      call $~lib/arraybuffer/ArrayBufferView~visit
       return
      end
+     local.get $0
+     local.get $1
+     call $class/MemberTypeInfer~visit
      return
     end
     local.get $0
@@ -2529,6 +2699,213 @@
  )
  (func $~start
   call $start:class
+ )
+ (func $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__data_end
+  i32.lt_s
+  if
+   i32.const 33520
+   i32.const 33568
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $class/MemberTypeInfer#constructor (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 12
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i64.const 0
+  i64.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store offset=8
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 12
+   i32.const 5
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store offset=4
+  local.get $1
+  call $~lib/object/Object#constructor
+  local.tee $this
+  i32.store
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store offset=4
+  local.get $1
+  i32.const 1
+  call $class/MemberTypeInfer#set:a
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store offset=4
+  local.get $1
+  global.get $class/outsideF32
+  call $class/MemberTypeInfer#set:b
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store offset=4
+  local.get $1
+  i32.const 432
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store offset=8
+  local.get $1
+  call $class/MemberTypeInfer#set:c
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 12
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+ (func $~lib/string/String.__eq (param $left i32) (param $right i32) (result i32)
+  (local $leftLength i32)
+  (local $3 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i64.const 0
+  i64.store
+  local.get $left
+  local.get $right
+  i32.eq
+  if
+   i32.const 1
+   local.set $3
+   global.get $~lib/memory/__stack_pointer
+   i32.const 8
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $3
+   return
+  end
+  local.get $left
+  i32.const 0
+  i32.eq
+  if (result i32)
+   i32.const 1
+  else
+   local.get $right
+   i32.const 0
+   i32.eq
+  end
+  if
+   i32.const 0
+   local.set $3
+   global.get $~lib/memory/__stack_pointer
+   i32.const 8
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $3
+   return
+  end
+  local.get $left
+  local.set $3
+  global.get $~lib/memory/__stack_pointer
+  local.get $3
+  i32.store
+  local.get $3
+  call $~lib/string/String#get:length
+  local.set $leftLength
+  local.get $leftLength
+  local.get $right
+  local.set $3
+  global.get $~lib/memory/__stack_pointer
+  local.get $3
+  i32.store
+  local.get $3
+  call $~lib/string/String#get:length
+  i32.ne
+  if
+   i32.const 0
+   local.set $3
+   global.get $~lib/memory/__stack_pointer
+   i32.const 8
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $3
+   return
+  end
+  local.get $left
+  local.set $3
+  global.get $~lib/memory/__stack_pointer
+  local.get $3
+  i32.store
+  local.get $3
+  i32.const 0
+  local.get $right
+  local.set $3
+  global.get $~lib/memory/__stack_pointer
+  local.get $3
+  i32.store offset=4
+  local.get $3
+  i32.const 0
+  local.get $leftLength
+  call $~lib/util/string/compareImpl
+  i32.eqz
+  local.set $3
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $3
+  return
+ )
+ (func $start:class
+  (local $0 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 12
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i64.const 0
+  i64.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store offset=8
+  i32.const 4
+  i32.const 4
+  i32.eq
+  drop
+  global.get $class/Animal.ONE
+  drop
+  i32.const 1
+  i32.const 2
+  call $class/Animal.add
+  drop
+  f32.const 1
+  f32.const 2
+  call $class/Animal.sub<f32>
+  drop
   memory.size
   i32.const 16
   i32.shl
@@ -2546,19 +2923,103 @@
   i32.const 320
   call $~lib/rt/itcms/initLazy
   global.set $~lib/rt/itcms/fromSpace
- )
- (func $~stack_check
+  i32.const 0
+  call $class/MemberTypeInfer#constructor
+  global.set $class/memberTypeInfer
+  global.get $class/memberTypeInfer
+  local.set $0
   global.get $~lib/memory/__stack_pointer
-  global.get $~lib/memory/__data_end
-  i32.lt_s
+  local.get $0
+  i32.store offset=8
+  local.get $0
+  call $class/MemberTypeInfer#get:a
+  drop
+  i32.const 464
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store
+  local.get $0
+  i32.const 464
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store offset=4
+  local.get $0
+  call $~lib/string/String.__eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 496
+   i32.const 53
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $class/memberTypeInfer
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store offset=8
+  local.get $0
+  call $class/MemberTypeInfer#get:b
+  drop
+  i32.const 544
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store
+  local.get $0
+  i32.const 544
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store offset=4
+  local.get $0
+  call $~lib/string/String.__eq
+  i32.eqz
   if
-   i32.const 33344
-   i32.const 33392
+   i32.const 0
+   i32.const 496
+   i32.const 54
    i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $class/memberTypeInfer
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store offset=8
+  local.get $0
+  call $class/MemberTypeInfer#get:c
+  drop
+  i32.const 576
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store
+  local.get $0
+  i32.const 576
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store offset=4
+  local.get $0
+  call $~lib/string/String.__eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 496
+   i32.const 55
    i32.const 1
    call $~lib/builtins/abort
    unreachable
   end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 12
+  i32.add
+  global.set $~lib/memory/__stack_pointer
  )
  (func $class/test (param $animal i32) (result i32)
   (local $ptr i32)
@@ -2685,7 +3146,7 @@
   if
    global.get $~lib/memory/__stack_pointer
    i32.const 16
-   i32.const 6
+   i32.const 7
    call $~lib/rt/itcms/__new
    local.tee $this
    i32.store
@@ -2728,8 +3189,8 @@
   i32.shr_u
   i32.gt_u
   if
-   i32.const 432
-   i32.const 480
+   i32.const 608
+   i32.const 656
    i32.const 70
    i32.const 60
    call $~lib/builtins/abort
@@ -2819,7 +3280,7 @@
   if
    global.get $~lib/memory/__stack_pointer
    i32.const 4
-   i32.const 5
+   i32.const 6
    call $~lib/rt/itcms/__new
    local.tee $this
    i32.store
diff --git a/tests/compiler/class.release.wat b/tests/compiler/class.release.wat
index 710aef17f0..f68b633010 100644
--- a/tests/compiler/class.release.wat
+++ b/tests/compiler/class.release.wat
@@ -3,10 +3,10 @@
  (type $1 (func (param i32)))
  (type $2 (func (param i32 i32)))
  (type $3 (func (param i32 i32) (result i32)))
- (type $4 (func (param i32 i32 i32 i32)))
- (type $5 (func (param i32 i32 i64)))
- (type $6 (func (result i32)))
- (type $7 (func (param i32) (result i32)))
+ (type $4 (func (param i32) (result i32)))
+ (type $5 (func (param i32 i32 i32 i32)))
+ (type $6 (func (param i32 i32 i64)))
+ (type $7 (func (result i32)))
  (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
  (global $~lib/rt/itcms/total (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/threshold (mut i32) (i32.const 0))
@@ -18,7 +18,8 @@
  (global $~lib/rt/itcms/white (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/fromSpace (mut i32) (i32.const 0))
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 34336))
+ (global $class/memberTypeInfer (mut i32) (i32.const 0))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 34516))
  (memory $0 1)
  (data $0 (i32.const 1036) "<")
  (data $0.1 (i32.const 1048) "\02\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e")
@@ -30,11 +31,22 @@
  (data $5.1 (i32.const 1304) "\02\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s")
  (data $7 (i32.const 1372) "<")
  (data $7.1 (i32.const 1384) "\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s")
- (data $8 (i32.const 1436) ",")
- (data $8.1 (i32.const 1448) "\02\00\00\00\1c\00\00\00I\00n\00v\00a\00l\00i\00d\00 \00l\00e\00n\00g\00t\00h")
- (data $9 (i32.const 1484) ",")
- (data $9.1 (i32.const 1496) "\02\00\00\00\1a\00\00\00~\00l\00i\00b\00/\00a\00r\00r\00a\00y\00.\00t\00s")
- (data $10 (i32.const 1536) "\07\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02\t")
+ (data $8 (i32.const 1436) "\1c")
+ (data $8.1 (i32.const 1448) "\02\00\00\00\06\00\00\00h\00h\00h")
+ (data $9 (i32.const 1468) "\1c")
+ (data $9.1 (i32.const 1480) "\02\00\00\00\06\00\00\00i\003\002")
+ (data $10 (i32.const 1500) ",")
+ (data $10.1 (i32.const 1512) "\02\00\00\00\10\00\00\00c\00l\00a\00s\00s\00.\00t\00s")
+ (data $11 (i32.const 1548) "\1c")
+ (data $11.1 (i32.const 1560) "\02\00\00\00\06\00\00\00f\003\002")
+ (data $12 (i32.const 1580) "\1c")
+ (data $12.1 (i32.const 1592) "\02\00\00\00\0c\00\00\00S\00t\00r\00i\00n\00g")
+ (data $13 (i32.const 1612) ",")
+ (data $13.1 (i32.const 1624) "\02\00\00\00\1c\00\00\00I\00n\00v\00a\00l\00i\00d\00 \00l\00e\00n\00g\00t\00h")
+ (data $14 (i32.const 1660) ",")
+ (data $14.1 (i32.const 1672) "\02\00\00\00\1a\00\00\00~\00l\00i\00b\00/\00a\00r\00r\00a\00y\00.\00t\00s")
+ (data $15 (i32.const 1712) "\08\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 ")
+ (data $15.1 (i32.const 1744) "\02\t")
  (export "testGenericInitializer" (func $class/testGenericInitializer))
  (export "memory" (memory $0))
  (export "test" (func $export:class/test))
@@ -42,9 +54,15 @@
  (func $~lib/rt/itcms/visitRoots
   (local $0 i32)
   (local $1 i32)
+  global.get $class/memberTypeInfer
+  local.tee $0
+  if
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
   i32.const 1248
   call $~lib/rt/itcms/__visit
-  i32.const 1456
+  i32.const 1632
   call $~lib/rt/itcms/__visit
   i32.const 1056
   call $~lib/rt/itcms/__visit
@@ -109,7 +127,7 @@
    local.get $1
    global.set $~lib/rt/itcms/iter
   end
-  block $__inlined_func$~lib/rt/itcms/Object#unlink$137
+  block $__inlined_func$~lib/rt/itcms/Object#unlink$153
    local.get $0
    i32.load offset=4
    i32.const -4
@@ -121,7 +139,7 @@
     i32.load offset=8
     i32.eqz
     local.get $0
-    i32.const 34336
+    i32.const 34516
     i32.lt_u
     i32.and
     i32.eqz
@@ -133,7 +151,7 @@
      call $~lib/builtins/abort
      unreachable
     end
-    br $__inlined_func$~lib/rt/itcms/Object#unlink$137
+    br $__inlined_func$~lib/rt/itcms/Object#unlink$153
    end
    local.get $0
    i32.load offset=8
@@ -170,7 +188,7 @@
    i32.const 1
   else
    local.get $1
-   i32.const 1536
+   i32.const 1712
    i32.load
    i32.gt_u
    if
@@ -184,7 +202,7 @@
    local.get $1
    i32.const 2
    i32.shl
-   i32.const 1540
+   i32.const 1716
    i32.add
    i32.load
    i32.const 32
@@ -768,10 +786,10 @@
   if
    unreachable
   end
-  i32.const 34336
+  i32.const 34528
   i32.const 0
   i32.store
-  i32.const 35904
+  i32.const 36096
   i32.const 0
   i32.store
   loop $for-loop|0
@@ -782,7 +800,7 @@
     local.get $0
     i32.const 2
     i32.shl
-    i32.const 34336
+    i32.const 34528
     i32.add
     i32.const 0
     i32.store offset=4
@@ -800,7 +818,7 @@
       i32.add
       i32.const 2
       i32.shl
-      i32.const 34336
+      i32.const 34528
       i32.add
       i32.const 0
       i32.store offset=96
@@ -818,14 +836,14 @@
     br $for-loop|0
    end
   end
-  i32.const 34336
-  i32.const 35908
+  i32.const 34528
+  i32.const 36100
   memory.size
   i64.extend_i32_s
   i64.const 16
   i64.shl
   call $~lib/rt/tlsf/addMemory
-  i32.const 34336
+  i32.const 34528
   global.set $~lib/rt/tlsf/ROOT
  )
  (func $~lib/rt/itcms/step (result i32)
@@ -910,7 +928,7 @@
      local.set $0
      loop $while-continue|0
       local.get $0
-      i32.const 34336
+      i32.const 34516
       i32.lt_u
       if
        local.get $0
@@ -1006,7 +1024,7 @@
      unreachable
     end
     local.get $0
-    i32.const 34336
+    i32.const 34516
     i32.lt_u
     if
      local.get $0
@@ -1029,7 +1047,7 @@
      i32.const 4
      i32.add
      local.tee $0
-     i32.const 34336
+     i32.const 34516
      i32.ge_u
      if
       global.get $~lib/rt/tlsf/ROOT
@@ -1240,7 +1258,7 @@
   global.get $~lib/rt/itcms/threshold
   i32.ge_u
   if
-   block $__inlined_func$~lib/rt/itcms/interrupt$71
+   block $__inlined_func$~lib/rt/itcms/interrupt$69
     i32.const 2048
     local.set $2
     loop $do-loop|0
@@ -1261,7 +1279,7 @@
       i32.const 1024
       i32.add
       global.set $~lib/rt/itcms/threshold
-      br $__inlined_func$~lib/rt/itcms/interrupt$71
+      br $__inlined_func$~lib/rt/itcms/interrupt$69
      end
      local.get $2
      i32.const 0
@@ -1537,59 +1555,58 @@
   memory.fill
   local.get $1
  )
- (func $~lib/array/Array<i32>#set:buffer (param $0 i32) (param $1 i32)
+ (func $~lib/rt/itcms/__link (param $0 i32) (param $1 i32)
   (local $2 i32)
-  local.get $0
   local.get $1
-  i32.store
+  i32.eqz
+  if
+   return
+  end
+  local.get $0
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1120
+   i32.const 295
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/rt/itcms/white
+  local.tee $2
   local.get $1
+  i32.const 20
+  i32.sub
+  local.tee $1
+  i32.load offset=4
+  i32.const 3
+  i32.and
+  i32.eq
   if
    local.get $0
-   i32.eqz
-   if
-    i32.const 0
-    i32.const 1120
-    i32.const 295
-    i32.const 14
-    call $~lib/builtins/abort
-    unreachable
-   end
-   global.get $~lib/rt/itcms/white
-   local.tee $2
-   local.get $1
    i32.const 20
    i32.sub
-   local.tee $1
    i32.load offset=4
    i32.const 3
    i32.and
+   local.tee $0
+   local.get $2
+   i32.eqz
    i32.eq
    if
+    local.get $1
+    call $~lib/rt/itcms/Object#makeGray
+   else
+    global.get $~lib/rt/itcms/state
+    i32.const 1
+    i32.eq
     local.get $0
-    i32.const 20
-    i32.sub
-    i32.load offset=4
     i32.const 3
-    i32.and
-    local.tee $0
-    local.get $2
-    i32.eqz
     i32.eq
+    i32.and
     if
      local.get $1
      call $~lib/rt/itcms/Object#makeGray
-    else
-     global.get $~lib/rt/itcms/state
-     i32.const 1
-     i32.eq
-     local.get $0
-     i32.const 3
-     i32.eq
-     i32.and
-     if
-      local.get $1
-      call $~lib/rt/itcms/Object#makeGray
-     end
     end
    end
   end
@@ -1604,7 +1621,7 @@
   global.set $~lib/memory/__stack_pointer
   block $folding-inner0
    global.get $~lib/memory/__stack_pointer
-   i32.const 1568
+   i32.const 1748
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1616,7 +1633,7 @@
    i32.store offset=8
    local.get $0
    i32.const 4
-   i32.const 5
+   i32.const 6
    call $~lib/rt/itcms/__new
    local.tee $0
    i32.store
@@ -1625,113 +1642,95 @@
    local.get $0
    i32.store offset=4
    local.get $1
-   i32.const 4
-   i32.sub
-   global.set $~lib/memory/__stack_pointer
-   global.get $~lib/memory/__stack_pointer
-   i32.const 1568
-   i32.lt_s
-   br_if $folding-inner0
-   global.get $~lib/memory/__stack_pointer
-   local.tee $2
-   i32.const 0
-   i32.store
-   local.get $0
-   i32.eqz
-   if
-    local.get $2
-    i32.const 0
-    i32.const 0
-    call $~lib/rt/itcms/__new
-    local.tee $0
-    i32.store
-   end
-   global.get $~lib/memory/__stack_pointer
-   i32.const 4
-   i32.add
-   global.set $~lib/memory/__stack_pointer
-   local.get $1
    local.get $0
+   call $~lib/object/Object#constructor
+   local.tee $1
    i32.store
    global.get $~lib/memory/__stack_pointer
-   local.get $0
+   local.get $1
    i32.store offset=4
    global.get $~lib/memory/__stack_pointer
    i32.const 16
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1568
+   i32.const 1748
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
-   local.tee $1
+   local.tee $0
    i64.const 0
    i64.store
-   local.get $1
+   local.get $0
    i64.const 0
    i64.store offset=8
-   local.get $1
+   local.get $0
    i32.const 16
-   i32.const 6
+   i32.const 7
    call $~lib/rt/itcms/__new
-   local.tee $1
+   local.tee $2
    i32.store
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
+   local.get $2
+   i32.const 0
+   i32.store
+   local.get $2
    i32.const 0
-   call $~lib/array/Array<i32>#set:buffer
+   call $~lib/rt/itcms/__link
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
+   local.get $2
    i32.const 0
    i32.store offset=4
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
+   local.get $2
    i32.const 0
    i32.store offset=8
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
+   local.get $2
    i32.const 0
    i32.store offset=12
    global.get $~lib/memory/__stack_pointer
    i32.const 32
    i32.const 1
    call $~lib/rt/itcms/__new
-   local.tee $2
+   local.tee $0
    i32.store offset=8
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
    global.get $~lib/memory/__stack_pointer
-   local.get $2
+   local.get $0
    i32.store offset=12
-   local.get $1
    local.get $2
-   call $~lib/array/Array<i32>#set:buffer
+   local.get $0
+   i32.store
+   local.get $2
+   local.get $0
+   call $~lib/rt/itcms/__link
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
    local.get $2
+   local.get $0
    i32.store offset=4
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
+   local.get $2
    i32.const 32
    i32.store offset=8
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=4
-   local.get $1
+   local.get $2
    i32.const 0
    i32.store offset=12
    global.get $~lib/memory/__stack_pointer
@@ -1739,19 +1738,22 @@
    i32.add
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   local.get $1
+   local.get $2
    i32.store offset=8
-   local.get $0
    local.get $1
-   call $~lib/array/Array<i32>#set:buffer
+   local.get $2
+   i32.store
+   local.get $1
+   local.get $2
+   call $~lib/rt/itcms/__link
    global.get $~lib/memory/__stack_pointer
    i32.const 12
    i32.add
    global.set $~lib/memory/__stack_pointer
    return
   end
-  i32.const 34368
-  i32.const 34416
+  i32.const 34544
+  i32.const 34592
   i32.const 1
   i32.const 1
   call $~lib/builtins/abort
@@ -1762,15 +1764,18 @@
   block $folding-inner0
    block $invalid
     block $~lib/array/Array<i32>
-     block $class/Animal<f64>
-      block $~lib/string/String
-       block $~lib/arraybuffer/ArrayBuffer
-        block $~lib/object/Object
-         local.get $0
-         i32.const 8
-         i32.sub
-         i32.load
-         br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $class/Animal<f64> $folding-inner0 $~lib/array/Array<i32> $invalid
+     block $class/MemberTypeInfer
+      block $class/Animal<f64>
+       block $~lib/string/String
+        block $~lib/arraybuffer/ArrayBuffer
+         block $~lib/object/Object
+          local.get $0
+          i32.const 8
+          i32.sub
+          i32.load
+          br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $class/Animal<f64> $class/MemberTypeInfer $folding-inner0 $~lib/array/Array<i32> $invalid
+         end
+         return
         end
         return
        end
@@ -1778,6 +1783,13 @@
       end
       return
      end
+     local.get $0
+     i32.load offset=8
+     local.tee $0
+     if
+      local.get $0
+      call $~lib/rt/itcms/__visit
+     end
      return
     end
     global.get $~lib/memory/__stack_pointer
@@ -1785,11 +1797,11 @@
     i32.sub
     global.set $~lib/memory/__stack_pointer
     global.get $~lib/memory/__stack_pointer
-    i32.const 1568
+    i32.const 1748
     i32.lt_s
     if
-     i32.const 34368
-     i32.const 34416
+     i32.const 34544
+     i32.const 34592
      i32.const 1
      i32.const 1
      call $~lib/builtins/abort
@@ -1822,38 +1834,407 @@
   end
  )
  (func $~start
-  memory.size
-  i32.const 16
-  i32.shl
-  i32.const 34336
+  (local $0 i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 12
   i32.sub
+  global.set $~lib/memory/__stack_pointer
+  block $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1748
+   i32.lt_s
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   i64.const 0
+   i64.store
+   local.get $0
+   i32.const 0
+   i32.store offset=8
+   memory.size
+   i32.const 16
+   i32.shl
+   i32.const 34516
+   i32.sub
+   i32.const 1
+   i32.shr_u
+   global.set $~lib/rt/itcms/threshold
+   i32.const 1172
+   i32.const 1168
+   i32.store
+   i32.const 1176
+   i32.const 1168
+   i32.store
+   i32.const 1168
+   global.set $~lib/rt/itcms/pinSpace
+   i32.const 1204
+   i32.const 1200
+   i32.store
+   i32.const 1208
+   i32.const 1200
+   i32.store
+   i32.const 1200
+   global.set $~lib/rt/itcms/toSpace
+   i32.const 1348
+   i32.const 1344
+   i32.store
+   i32.const 1352
+   i32.const 1344
+   i32.store
+   i32.const 1344
+   global.set $~lib/rt/itcms/fromSpace
+   local.get $0
+   i32.const 12
+   i32.sub
+   global.set $~lib/memory/__stack_pointer
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1748
+   i32.lt_s
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   i64.const 0
+   i64.store
+   local.get $0
+   i32.const 0
+   i32.store offset=8
+   local.get $0
+   i32.const 12
+   i32.const 5
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   local.tee $1
+   local.get $0
+   i32.store offset=4
+   local.get $1
+   local.get $0
+   call $~lib/object/Object#constructor
+   local.tee $0
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store offset=4
+   local.get $0
+   i32.const 1
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store offset=4
+   local.get $0
+   f32.const 1.2000000476837158
+   f32.store offset=4
+   global.get $~lib/memory/__stack_pointer
+   local.get $0
+   i32.store offset=4
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1456
+   i32.store offset=8
+   local.get $0
+   i32.const 1456
+   i32.store offset=8
+   local.get $0
+   i32.const 1456
+   call $~lib/rt/itcms/__link
+   global.get $~lib/memory/__stack_pointer
+   i32.const 12
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $0
+   global.set $class/memberTypeInfer
+   global.get $~lib/memory/__stack_pointer
+   global.get $class/memberTypeInfer
+   local.tee $0
+   i32.store offset=8
+   local.get $0
+   i32.load
+   drop
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1488
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1488
+   i32.store offset=4
+   i32.const 1488
+   i32.const 1488
+   call $~lib/string/String.__eq
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 1520
+    i32.const 53
+    i32.const 1
+    call $~lib/builtins/abort
+    unreachable
+   end
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   global.get $class/memberTypeInfer
+   local.tee $1
+   i32.store offset=8
+   local.get $1
+   f32.load offset=4
+   drop
+   local.get $0
+   i32.const 1568
+   i32.store
+   local.get $0
+   i32.const 1568
+   i32.store offset=4
+   i32.const 1568
+   i32.const 1568
+   call $~lib/string/String.__eq
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 1520
+    i32.const 54
+    i32.const 1
+    call $~lib/builtins/abort
+    unreachable
+   end
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   global.get $class/memberTypeInfer
+   local.tee $1
+   i32.store offset=8
+   local.get $1
+   i32.load offset=8
+   drop
+   local.get $0
+   i32.const 1600
+   i32.store
+   local.get $0
+   i32.const 1600
+   i32.store offset=4
+   i32.const 1600
+   i32.const 1600
+   call $~lib/string/String.__eq
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 1520
+    i32.const 55
+    i32.const 1
+    call $~lib/builtins/abort
+    unreachable
+   end
+   global.get $~lib/memory/__stack_pointer
+   i32.const 12
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   return
+  end
+  i32.const 34544
+  i32.const 34592
   i32.const 1
-  i32.shr_u
-  global.set $~lib/rt/itcms/threshold
-  i32.const 1172
-  i32.const 1168
-  i32.store
-  i32.const 1176
-  i32.const 1168
-  i32.store
-  i32.const 1168
-  global.set $~lib/rt/itcms/pinSpace
-  i32.const 1204
-  i32.const 1200
-  i32.store
-  i32.const 1208
-  i32.const 1200
-  i32.store
-  i32.const 1200
-  global.set $~lib/rt/itcms/toSpace
-  i32.const 1348
-  i32.const 1344
-  i32.store
-  i32.const 1352
-  i32.const 1344
+  i32.const 1
+  call $~lib/builtins/abort
+  unreachable
+ )
+ (func $~lib/string/String.__eq (param $0 i32) (param $1 i32) (result i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1748
+  i32.lt_s
+  if
+   i32.const 34544
+   i32.const 34592
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.tee $2
+  i64.const 0
+  i64.store
+  local.get $0
+  local.get $1
+  i32.eq
+  if
+   local.get $2
+   i32.const 8
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   i32.const 1
+   return
+  end
+  block $folding-inner0
+   local.get $1
+   i32.eqz
+   local.get $0
+   i32.eqz
+   i32.or
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $4
+   local.tee $2
+   local.get $0
+   i32.store
+   local.get $0
+   i32.const 20
+   i32.sub
+   i32.load offset=16
+   i32.const 1
+   i32.shr_u
+   local.set $3
+   local.get $2
+   local.get $1
+   i32.store
+   local.get $3
+   local.get $1
+   i32.const 20
+   i32.sub
+   i32.load offset=16
+   i32.const 1
+   i32.shr_u
+   i32.ne
+   br_if $folding-inner0
+   local.get $4
+   local.get $0
+   i32.store
+   local.get $0
+   local.set $2
+   local.get $4
+   local.get $1
+   i32.store offset=4
+   local.get $3
+   local.tee $0
+   i32.const 4
+   i32.ge_u
+   if (result i32)
+    local.get $2
+    i32.const 7
+    i32.and
+    local.get $1
+    i32.const 7
+    i32.and
+    i32.or
+   else
+    i32.const 1
+   end
+   i32.eqz
+   if
+    loop $do-loop|0
+     local.get $2
+     i64.load
+     local.get $1
+     i64.load
+     i64.eq
+     if
+      local.get $2
+      i32.const 8
+      i32.add
+      local.set $2
+      local.get $1
+      i32.const 8
+      i32.add
+      local.set $1
+      local.get $0
+      i32.const 4
+      i32.sub
+      local.tee $0
+      i32.const 4
+      i32.ge_u
+      br_if $do-loop|0
+     end
+    end
+   end
+   block $__inlined_func$~lib/util/string/compareImpl$85
+    loop $while-continue|1
+     local.get $0
+     local.tee $3
+     i32.const 1
+     i32.sub
+     local.set $0
+     local.get $3
+     if
+      local.get $2
+      i32.load16_u
+      local.tee $5
+      local.get $1
+      i32.load16_u
+      local.tee $4
+      i32.sub
+      local.set $3
+      local.get $4
+      local.get $5
+      i32.ne
+      br_if $__inlined_func$~lib/util/string/compareImpl$85
+      local.get $2
+      i32.const 2
+      i32.add
+      local.set $2
+      local.get $1
+      i32.const 2
+      i32.add
+      local.set $1
+      br $while-continue|1
+     end
+    end
+    i32.const 0
+    local.set $3
+   end
+   global.get $~lib/memory/__stack_pointer
+   i32.const 8
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $3
+   i32.eqz
+   return
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  i32.const 0
+ )
+ (func $~lib/object/Object#constructor (param $0 i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1748
+  i32.lt_s
+  if
+   i32.const 34544
+   i32.const 34592
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.tee $1
+  i32.const 0
   i32.store
-  i32.const 1344
-  global.set $~lib/rt/itcms/fromSpace
+  local.get $0
+  i32.eqz
+  if
+   local.get $1
+   i32.const 0
+   i32.const 0
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $0
  )
  (func $export:class/test (param $0 i32) (result i32)
   (local $1 i32)
@@ -1863,7 +2244,7 @@
   global.set $~lib/memory/__stack_pointer
   block $folding-inner0
    global.get $~lib/memory/__stack_pointer
-   i32.const 1568
+   i32.const 1748
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1875,7 +2256,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1568
+   i32.const 1748
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1938,8 +2319,8 @@
    local.get $0
    return
   end
-  i32.const 34368
-  i32.const 34416
+  i32.const 34544
+  i32.const 34592
   i32.const 1
   i32.const 1
   call $~lib/builtins/abort
diff --git a/tests/compiler/class.ts b/tests/compiler/class.ts
index 93a95068da..9ceeb304bd 100644
--- a/tests/compiler/class.ts
+++ b/tests/compiler/class.ts
@@ -40,3 +40,16 @@ class GenericInitializer<T> {
 export function testGenericInitializer(): void {
   new GenericInitializer<i32>();
 }
+
+
+let outsideF32: f32 = 1.2;
+class MemberTypeInfer {
+  a = 1;
+  b = outsideF32;
+  c = "hhh";
+}
+
+let memberTypeInfer = new MemberTypeInfer();
+assert(nameof(memberTypeInfer.a) == nameof<i32>());
+assert(nameof(memberTypeInfer.b) == nameof<f32>());
+assert(nameof(memberTypeInfer.c) == nameof<string>());
diff --git a/tests/parser/class.ts b/tests/parser/class.ts
index 8f9c997e6f..0a9c656916 100644
--- a/tests/parser/class.ts
+++ b/tests/parser/class.ts
@@ -41,3 +41,9 @@ export class Invalid<T> {
   // ERROR 1042: "'override' modifier cannot be used here."
   override overrideMethod(): void {}
 }
+
+export class MemberTypeInfer {
+  a = 1;
+  b = 1.2;
+  c = "hhh";
+}
diff --git a/tests/parser/class.ts.fixture.ts b/tests/parser/class.ts.fixture.ts
index 8d429d4f5c..9fc7658f87 100644
--- a/tests/parser/class.ts.fixture.ts
+++ b/tests/parser/class.ts.fixture.ts
@@ -19,6 +19,11 @@ export class Invalid<T> {
   declare declareMethod(): i32 {}
   overrideMethod(): void {}
 }
+export class MemberTypeInfer {
+  a = 1;
+  b = 1.2;
+  c = "hhh";
+}
 // ERROR 1092: "Type parameters cannot appear on a constructor declaration." in class.ts(15,14+3)
 // ERROR 1110: "Type expected." in class.ts(18,21+0)
 // ERROR 1094: "An accessor cannot have type parameters." in class.ts(23,21+3)