diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index 5e506e9c3cd5..84607aa31cd6 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -3654,8 +3654,7 @@ AbortReasonOr<MBinaryArithInstruction*> IonBuilder::binaryArithEmitSpecialized(
     MDefinition::Opcode op, MIRType specialization, MDefinition* left,
     MDefinition* right) {
   MBinaryArithInstruction* ins =
-      MBinaryArithInstruction::New(alloc(), op, left, right);
-  ins->setSpecialization(specialization);
+      MBinaryArithInstruction::New(alloc(), op, left, right, specialization);
 
   if (op == MDefinition::Opcode::Add || op == MDefinition::Opcode::Mul) {
     ins->setCommutative();
diff --git a/js/src/jit/MIR.cpp b/js/src/jit/MIR.cpp
index 8425258d0dbb..78b3f9398a06 100644
--- a/js/src/jit/MIR.cpp
+++ b/js/src/jit/MIR.cpp
@@ -2787,18 +2787,20 @@ void MBinaryArithInstruction::printOpcode(GenericPrinter& out) const {
 MBinaryArithInstruction* MBinaryArithInstruction::New(TempAllocator& alloc,
                                                       Opcode op,
                                                       MDefinition* left,
-                                                      MDefinition* right) {
+                                                      MDefinition* right,
+                                                      MIRType specialization) {
+  MOZ_ASSERT(IsNumberType(specialization));
   switch (op) {
     case Opcode::Add:
-      return MAdd::New(alloc, left, right);
+      return MAdd::New(alloc, left, right, specialization);
     case Opcode::Sub:
-      return MSub::New(alloc, left, right);
+      return MSub::New(alloc, left, right, specialization);
     case Opcode::Mul:
-      return MMul::New(alloc, left, right);
+      return MMul::New(alloc, left, right, specialization);
     case Opcode::Div:
-      return MDiv::New(alloc, left, right);
+      return MDiv::New(alloc, left, right, specialization);
     case Opcode::Mod:
-      return MMod::New(alloc, left, right);
+      return MMod::New(alloc, left, right, specialization);
     default:
       MOZ_CRASH("unexpected binary opcode");
   }
diff --git a/js/src/jit/MIR.h b/js/src/jit/MIR.h
index 1c5b5ee91095..98ff0dd5be94 100644
--- a/js/src/jit/MIR.h
+++ b/js/src/jit/MIR.h
@@ -4788,7 +4788,8 @@ class MBinaryArithInstruction : public MBinaryInstruction,
   }
 
   static MBinaryArithInstruction* New(TempAllocator& alloc, Opcode op,
-                                      MDefinition* left, MDefinition* right);
+                                      MDefinition* left, MDefinition* right,
+                                      MIRType specialization);
 
   bool constantDoubleResult(TempAllocator& alloc);
 
@@ -5709,6 +5710,10 @@ class MMod : public MBinaryArithInstruction {
                    MDefinition* right) {
     return new (alloc) MMod(left, right, MIRType::Value);
   }
+  static MMod* New(TempAllocator& alloc, MDefinition* left, MDefinition* right,
+                   MIRType type) {
+    return new (alloc) MMod(left, right, type);
+  }
   static MMod* New(
       TempAllocator& alloc, MDefinition* left, MDefinition* right, MIRType type,
       bool unsignd, bool trapOnError = false,
diff --git a/js/src/jsapi-tests/testJitGVN.cpp b/js/src/jsapi-tests/testJitGVN.cpp
index a9e96122f1be..4dd8d64fdee8 100644
--- a/js/src/jsapi-tests/testJitGVN.cpp
+++ b/js/src/jsapi-tests/testJitGVN.cpp
@@ -267,9 +267,9 @@ BEGIN_TEST(testJitGVN_PinnedPhis) {
 
   innerBackedge->end(MGoto::New(func.alloc, innerHeader));
 
-  MInstruction* z4 = MAdd::New(func.alloc, phi0, phi1);
+  MInstruction* z4 = MAdd::New(func.alloc, phi0, phi1, MIRType::Int32);
   MConstant* z5 = MConstant::New(func.alloc, Int32Value(4));
-  MInstruction* z6 = MAdd::New(func.alloc, phi2, phi3);
+  MInstruction* z6 = MAdd::New(func.alloc, phi2, phi3, MIRType::Int32);
   MConstant* z7 = MConstant::New(func.alloc, Int32Value(6));
   MOZ_RELEASE_ASSERT(phi0->addInputSlow(z4));
   MOZ_RELEASE_ASSERT(phi1->addInputSlow(z5));