diff --git a/kani-compiler/src/codegen_cprover_gotoc/codegen/intrinsic.rs b/kani-compiler/src/codegen_cprover_gotoc/codegen/intrinsic.rs
index 6d3db1666407..96f757e22aeb 100644
--- a/kani-compiler/src/codegen_cprover_gotoc/codegen/intrinsic.rs
+++ b/kani-compiler/src/codegen_cprover_gotoc/codegen/intrinsic.rs
@@ -272,6 +272,14 @@ impl GotocCtx<'_, '_> {
             Intrinsic::AddWithOverflow => {
                 self.codegen_op_with_overflow(BinaryOperator::OverflowResultPlus, fargs, place, loc)
             }
+            Intrinsic::AlignOf => {
+                let genarg = instance.args();
+                let tys = genarg.0.clone();
+                let t = tys.first().unwrap().ty().unwrap();
+                let layout = self.layout_of_stable(*t);
+                let expr = Expr::int_constant(layout.align.abi.bytes(), Type::size_t());
+                self.codegen_expr_to_place_stable(place, expr, loc)
+            }
             Intrinsic::ArithOffset => self.codegen_arith_offset(fargs, place, loc),
             Intrinsic::AssertInhabited => {
                 self.codegen_assert_intrinsic(instance, intrinsic_str, span)
@@ -481,6 +489,15 @@ impl GotocCtx<'_, '_> {
                 loc,
             ),
             Intrinsic::SimdXor => codegen_intrinsic_binop!(bitxor),
+            Intrinsic::SizeOf => {
+                let genarg = instance.args();
+                let tys = genarg.0.clone();
+                let t = tys.first().unwrap().ty().unwrap();
+                let layout = self.layout_of_stable(*t);
+                let expr = Expr::int_constant(layout.size.bytes_usize(), Type::size_t())
+                    .with_size_of_annotation(self.codegen_ty_stable(*t));
+                self.codegen_expr_to_place_stable(place, expr, loc)
+            }
             Intrinsic::SqrtF32 => codegen_simple_intrinsic!(Sqrtf),
             Intrinsic::SqrtF64 => codegen_simple_intrinsic!(Sqrt),
             Intrinsic::SubWithOverflow => self.codegen_op_with_overflow(
diff --git a/kani-compiler/src/codegen_cprover_gotoc/codegen/rvalue.rs b/kani-compiler/src/codegen_cprover_gotoc/codegen/rvalue.rs
index 93ee106188b4..6267b96bdbca 100644
--- a/kani-compiler/src/codegen_cprover_gotoc/codegen/rvalue.rs
+++ b/kani-compiler/src/codegen_cprover_gotoc/codegen/rvalue.rs
@@ -827,9 +827,6 @@ impl GotocCtx<'_, '_> {
             Rvalue::NullaryOp(k, t) => {
                 let layout = self.layout_of_stable(*t);
                 match k {
-                    NullOp::SizeOf => Expr::int_constant(layout.size.bytes_usize(), Type::size_t())
-                        .with_size_of_annotation(self.codegen_ty_stable(*t)),
-                    NullOp::AlignOf => Expr::int_constant(layout.align.abi.bytes(), Type::size_t()),
                     NullOp::OffsetOf(fields) => Expr::int_constant(
                         self.tcx
                             .offset_of_subfield(
diff --git a/kani-compiler/src/intrinsics.rs b/kani-compiler/src/intrinsics.rs
index bf832aa91a2f..1784d25269c7 100644
--- a/kani-compiler/src/intrinsics.rs
+++ b/kani-compiler/src/intrinsics.rs
@@ -14,6 +14,7 @@ use rustc_public::{
 #[derive(Clone, Debug)]
 pub enum Intrinsic {
     AddWithOverflow,
+    AlignOf,
     AlignOfVal,
     ArithOffset,
     AssertInhabited,
@@ -123,6 +124,7 @@ pub enum Intrinsic {
     SimdShuffle(String),
     SimdSub,
     SimdXor,
+    SizeOf,
     SizeOfVal,
     SqrtF32,
     SqrtF64,
@@ -177,9 +179,10 @@ impl Intrinsic {
                 assert_sig_matches!(sig, _, _ => RigidTy::Tuple(_));
                 Self::AddWithOverflow
             }
-            "align_of" => unreachable!(
-                "Expected `core::intrinsics::align_of` to be handled by NullOp::SizeOf"
-            ),
+            "align_of" => {
+                Self::AlignOf
+                //"Expected `core::intrinsics::align_of` to be handled by NullOp::SizeOf"
+            }
             "align_of_val" => {
                 assert_sig_matches!(sig, RigidTy::RawPtr(_, Mutability::Not) => RigidTy::Uint(UintTy::Usize));
                 Self::AlignOfVal
@@ -356,9 +359,7 @@ impl Intrinsic {
                 assert_sig_matches!(sig, _, _ => _);
                 Self::SaturatingSub
             }
-            "size_of" => {
-                unreachable!("Expected `core::intrinsics::size_of` to be handled by NullOp::SizeOf")
-            }
+            "size_of" => Self::SizeOf,
             "size_of_val" => {
                 assert_sig_matches!(sig, RigidTy::RawPtr(_, Mutability::Not) => RigidTy::Uint(UintTy::Usize));
                 Self::SizeOfVal
diff --git a/kani-compiler/src/kani_middle/transform/internal_mir.rs b/kani-compiler/src/kani_middle/transform/internal_mir.rs
index 4db9d4cca4c3..9bcd545628ee 100644
--- a/kani-compiler/src/kani_middle/transform/internal_mir.rs
+++ b/kani-compiler/src/kani_middle/transform/internal_mir.rs
@@ -195,8 +195,6 @@ impl RustcInternalMir for NullOp {
 
     fn internal_mir<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Self::T<'tcx> {
         match self {
-            NullOp::SizeOf => rustc_middle::mir::NullOp::SizeOf,
-            NullOp::AlignOf => rustc_middle::mir::NullOp::AlignOf,
             NullOp::OffsetOf(offsets) => rustc_middle::mir::NullOp::OffsetOf(
                 tcx.mk_offset_of(
                     offsets
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 38c9708c1f41..af6307fd8c47 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -2,5 +2,5 @@
 # SPDX-License-Identifier: Apache-2.0 OR MIT
 
 [toolchain]
-channel = "nightly-2025-10-23"
+channel = "nightly-2025-10-24"
 components = ["llvm-tools", "rustc-dev", "rust-src", "rustfmt"]
diff --git a/tests/kani/Drop/drop_after_moving_across_channel.rs b/tests/slow/tokio-proofs/src/drop_after_moving_across_channel.rs
similarity index 100%
rename from tests/kani/Drop/drop_after_moving_across_channel.rs
rename to tests/slow/tokio-proofs/src/drop_after_moving_across_channel.rs