diff --git a/src/verilog/verilog_elaborate.cpp b/src/verilog/verilog_elaborate.cpp
index cf7561c6a..9cc0a7f4c 100644
--- a/src/verilog/verilog_elaborate.cpp
+++ b/src/verilog/verilog_elaborate.cpp
@@ -236,7 +236,7 @@ void verilog_typecheckt::collect_symbols(const verilog_declt &decl)
         if(declarator.type().is_nil())
           symbol.type = type;
         else if(declarator.type().id() == ID_verilog_unpacked_array)
-          symbol.type = array_type(declarator.type(), type);
+          symbol.type = unpacked_array_type(declarator.type(), type);
         else
         {
           throw errort().with_location(declarator.source_location())
@@ -423,7 +423,7 @@ void verilog_typecheckt::collect_symbols(const verilog_declt &decl)
       if(declarator.type().is_nil())
         symbol.type = type;
       else if(declarator.type().id() == ID_verilog_unpacked_array)
-        symbol.type = array_type(declarator.type(), type);
+        symbol.type = unpacked_array_type(declarator.type(), type);
       else
       {
         throw errort().with_location(symbol.location)
@@ -490,7 +490,7 @@ void verilog_typecheckt::collect_symbols(const verilog_declt &decl)
       if(declarator.type().is_nil())
         symbol.type = type;
       else if(declarator.type().id() == ID_verilog_unpacked_array)
-        symbol.type = array_type(declarator.type(), type);
+        symbol.type = unpacked_array_type(declarator.type(), type);
       else
       {
         throw errort().with_location(symbol.location)
diff --git a/src/verilog/verilog_typecheck_expr.h b/src/verilog/verilog_typecheck_expr.h
index 8ce588850..99ba701da 100644
--- a/src/verilog/verilog_typecheck_expr.h
+++ b/src/verilog/verilog_typecheck_expr.h
@@ -64,7 +64,7 @@ class verilog_typecheck_exprt:public verilog_typecheck_baset
 
   typet convert_type(const typet &);
   typet convert_enum(const class verilog_enum_typet &);
-  array_typet array_type(const irept &src, const typet &element_type);
+  array_typet unpacked_array_type(const typet &src, const typet &element_type);
 
   void convert_range(
     const exprt &range,
diff --git a/src/verilog/verilog_typecheck_type.cpp b/src/verilog/verilog_typecheck_type.cpp
index 0e0f5b57d..f595bbada 100644
--- a/src/verilog/verilog_typecheck_type.cpp
+++ b/src/verilog/verilog_typecheck_type.cpp
@@ -16,7 +16,7 @@ Author: Daniel Kroening, kroening@kroening.com
 
 /*******************************************************************\
 
-Function: verilog_typecheck_exprt::array_type
+Function: verilog_typecheck_exprt::unpacked_array_type
 
   Inputs:
 
@@ -26,8 +26,9 @@ Function: verilog_typecheck_exprt::array_type
 
 \*******************************************************************/
 
-array_typet
-verilog_typecheck_exprt::array_type(const irept &src, const typet &element_type)
+array_typet verilog_typecheck_exprt::unpacked_array_type(
+  const typet &src,
+  const typet &element_type)
 {
   // int whatnot[x:y];
   // 'src' is yet to be converted, but 'element_type' is already converted.
@@ -57,13 +58,14 @@ verilog_typecheck_exprt::array_type(const irept &src, const typet &element_type)
     offset = 0;
     if(size < 0)
     {
+      // The size must be positive. 1800-2017 7.4.2
       throw errort().with_location(size_expr.find_source_location())
         << "array size must be nonnegative";
     }
   }
   else
   {
-    throw errort() << "array must have range or size";
+    throw errort() << "unpacked array must have range or size";
   }
 
   const typet src_subtype =
@@ -77,7 +79,7 @@ verilog_typecheck_exprt::array_type(const irept &src, const typet &element_type)
   if(src_subtype.is_nil())
     array_subtype = element_type;
   else
-    array_subtype = array_type(src_subtype, element_type);
+    array_subtype = unpacked_array_type(src_subtype, element_type);
 
   const exprt final_size_expr = from_integer(size, integer_typet());
   array_typet result(array_subtype, final_size_expr);