diff --git a/src/wasm.h b/src/wasm.h
index 601acbadc80..3007b07f7f4 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -953,9 +953,9 @@ class Call : public SpecificExpression<Expression::CallId> {
 public:
   Call(MixedArena& allocator) : operands(allocator) {}
 
+  bool isReturn = false;
   ExpressionList operands;
   Name target;
-  bool isReturn = false;
 
   void finalize();
 };
@@ -963,11 +963,12 @@ class Call : public SpecificExpression<Expression::CallId> {
 class CallIndirect : public SpecificExpression<Expression::CallIndirectId> {
 public:
   CallIndirect(MixedArena& allocator) : operands(allocator) {}
+
+  bool isReturn = false;
   HeapType heapType;
   ExpressionList operands;
   Expression* target;
   Name table;
-  bool isReturn = false;
 
   void finalize();
 };
@@ -1061,12 +1062,12 @@ class AtomicRMW : public SpecificExpression<Expression::AtomicRMWId> {
   AtomicRMW(MixedArena& allocator) : AtomicRMW() {}
 
   AtomicRMWOp op;
+  MemoryOrder order = MemoryOrder::SeqCst;
   uint8_t bytes;
   Address offset;
   Expression* ptr;
   Expression* value;
   Name memory;
-  MemoryOrder order = MemoryOrder::SeqCst;
 
   void finalize();
 };
@@ -1077,12 +1078,12 @@ class AtomicCmpxchg : public SpecificExpression<Expression::AtomicCmpxchgId> {
   AtomicCmpxchg(MixedArena& allocator) : AtomicCmpxchg() {}
 
   uint8_t bytes;
+  MemoryOrder order = MemoryOrder::SeqCst;
   Address offset;
   Expression* ptr;
   Expression* expected;
   Expression* replacement;
   Name memory;
-  MemoryOrder order = MemoryOrder::SeqCst;
 
   void finalize();
 };
@@ -1146,9 +1147,9 @@ class SIMDReplace : public SpecificExpression<Expression::SIMDReplaceId> {
   SIMDReplace() = default;
   SIMDReplace(MixedArena& allocator) : SIMDReplace() {}
 
+  uint8_t index;
   SIMDReplaceOp op;
   Expression* vec;
-  uint8_t index;
   Expression* value;
 
   void finalize();
@@ -1663,8 +1664,8 @@ class I31Get : public SpecificExpression<Expression::I31GetId> {
   I31Get() = default;
   I31Get(MixedArena& allocator) {}
 
-  Expression* i31;
   bool signed_ = false;
+  Expression* i31;
 
   void finalize();
 };
@@ -1672,9 +1673,10 @@ class I31Get : public SpecificExpression<Expression::I31GetId> {
 class CallRef : public SpecificExpression<Expression::CallRefId> {
 public:
   CallRef(MixedArena& allocator) : operands(allocator) {}
+
+  bool isReturn = false;
   ExpressionList operands;
   Expression* target;
-  bool isReturn = false;
 
   void finalize();
 };
@@ -1794,10 +1796,10 @@ class StructRMW : public SpecificExpression<Expression::StructRMWId> {
   StructRMW(MixedArena& allocator) {}
 
   AtomicRMWOp op;
+  MemoryOrder order;
   Index index;
   Expression* ref;
   Expression* value;
-  MemoryOrder order;
 
   void finalize();
 };
@@ -1807,11 +1809,11 @@ class StructCmpxchg : public SpecificExpression<Expression::StructCmpxchgId> {
   StructCmpxchg() = default;
   StructCmpxchg(MixedArena& allocator) {}
 
+  MemoryOrder order;
   Index index;
   Expression* ref;
   Expression* expected;
   Expression* replacement;
-  MemoryOrder order;
 
   void finalize();
 };
@@ -2040,11 +2042,11 @@ class ArrayRMW : public SpecificExpression<Expression::ArrayRMWId> {
   ArrayRMW() = default;
   ArrayRMW(MixedArena& allocator) {}
 
+  MemoryOrder order;
   AtomicRMWOp op;
   Expression* ref;
   Expression* index;
   Expression* value;
-  MemoryOrder order;
 
   void finalize();
 };
@@ -2054,11 +2056,11 @@ class ArrayCmpxchg : public SpecificExpression<Expression::ArrayCmpxchgId> {
   ArrayCmpxchg() = default;
   ArrayCmpxchg(MixedArena& allocator) {}
 
+  MemoryOrder order;
   Expression* ref;
   Expression* index;
   Expression* expected;
   Expression* replacement;
-  MemoryOrder order;
 
   void finalize();
 };
diff --git a/test/gtest/sizes.cpp b/test/gtest/sizes.cpp
index a421b56fa54..913427f617e 100644
--- a/test/gtest/sizes.cpp
+++ b/test/gtest/sizes.cpp
@@ -16,8 +16,8 @@ TEST(SizesTest, ExpressionSizes) {
   EXPECT_EQ(sizeof(Loop), 32u);
   EXPECT_EQ(sizeof(Break), 40u);
   EXPECT_EQ(sizeof(Switch), 72u);
-  EXPECT_EQ(sizeof(Call), 64u);
-  EXPECT_EQ(sizeof(CallIndirect), 80u);
+  EXPECT_EQ(sizeof(Call), 56u);
+  EXPECT_EQ(sizeof(CallIndirect), 72u);
   EXPECT_EQ(sizeof(LocalGet), 16u);
   EXPECT_EQ(sizeof(LocalSet), 24u);
   EXPECT_EQ(sizeof(GlobalGet), 24u);
@@ -34,14 +34,14 @@ TEST(SizesTest, ExpressionSizes) {
   EXPECT_EQ(sizeof(MemoryGrow), 32u);
   EXPECT_EQ(sizeof(Nop), 16u);
   EXPECT_EQ(sizeof(Unreachable), 16u);
-  EXPECT_EQ(sizeof(AtomicRMW), 64u);
-  EXPECT_EQ(sizeof(AtomicCmpxchg), 64u);
+  EXPECT_EQ(sizeof(AtomicRMW), 56u);
+  EXPECT_EQ(sizeof(AtomicCmpxchg), 56u);
   EXPECT_EQ(sizeof(AtomicWait), 64u);
   EXPECT_EQ(sizeof(AtomicNotify), 48u);
   EXPECT_EQ(sizeof(AtomicFence), 16u);
   EXPECT_EQ(sizeof(Pause), 16u);
   EXPECT_EQ(sizeof(SIMDExtract), 24u);
-  EXPECT_EQ(sizeof(SIMDReplace), 40u);
+  EXPECT_EQ(sizeof(SIMDReplace), 32u);
   EXPECT_EQ(sizeof(SIMDShuffle), 48u);
   EXPECT_EQ(sizeof(SIMDTernary), 40u);
   EXPECT_EQ(sizeof(SIMDShift), 32u);
@@ -72,8 +72,8 @@ TEST(SizesTest, ExpressionSizes) {
   EXPECT_EQ(sizeof(TupleMake), 48u);
   EXPECT_EQ(sizeof(TupleExtract), 24u);
   EXPECT_EQ(sizeof(RefI31), 24u);
-  EXPECT_EQ(sizeof(I31Get), 32u);
-  EXPECT_EQ(sizeof(CallRef), 64u);
+  EXPECT_EQ(sizeof(I31Get), 24u);
+  EXPECT_EQ(sizeof(CallRef), 56u);
   EXPECT_EQ(sizeof(RefTest), 32u);
   EXPECT_EQ(sizeof(RefCast), 32u);
   EXPECT_EQ(sizeof(RefGetDesc), 24u);
@@ -81,8 +81,8 @@ TEST(SizesTest, ExpressionSizes) {
   EXPECT_EQ(sizeof(StructNew), 56u);
   EXPECT_EQ(sizeof(StructGet), 24u);
   EXPECT_EQ(sizeof(StructSet), 32u);
-  EXPECT_EQ(sizeof(StructRMW), 48u);
-  EXPECT_EQ(sizeof(StructCmpxchg), 48u);
+  EXPECT_EQ(sizeof(StructRMW), 40u);
+  EXPECT_EQ(sizeof(StructCmpxchg), 40u);
   EXPECT_EQ(sizeof(ArrayNew), 32u);
   EXPECT_EQ(sizeof(ArrayNewData), 40u);
   EXPECT_EQ(sizeof(ArrayNewElem), 40u);
@@ -96,8 +96,8 @@ TEST(SizesTest, ExpressionSizes) {
   EXPECT_EQ(sizeof(ArrayFill), 48u);
   EXPECT_EQ(sizeof(ArrayInitData), 56u);
   EXPECT_EQ(sizeof(ArrayInitElem), 56u);
-  EXPECT_EQ(sizeof(ArrayRMW), 48u);
-  EXPECT_EQ(sizeof(ArrayCmpxchg), 56u);
+  EXPECT_EQ(sizeof(ArrayRMW), 40u);
+  EXPECT_EQ(sizeof(ArrayCmpxchg), 48u);
   EXPECT_EQ(sizeof(RefAs), 24u);
   EXPECT_EQ(sizeof(StringNew), 40u);
   EXPECT_EQ(sizeof(StringConst), 24u);