--- a/js/src/jit/none/LIR-none.h
+++ b/js/src/jit/none/LIR-none.h
@@ -38,20 +38,20 @@ class LTableSwitchV : public LInstructio
 
     const LDefinition* tempInt() { MOZ_CRASH(); }
     const LDefinition* tempFloat() { MOZ_CRASH(); }
     const LDefinition* tempPointer() { MOZ_CRASH(); }
 
     static const size_t InputValue = 0;
 };
 
-class LWasmUint32ToFloat32 : public LInstruction
+class LWasmUint32ToFloat32 : public LInstructionHelper<1, 1, 0>
 {
   public:
-    LWasmUint32ToFloat32(const LAllocation& ) { MOZ_CRASH(); }
+    LWasmUint32ToFloat32(const LAllocation&) { MOZ_CRASH(); }
 };
 
 class LUnbox : public LInstructionHelper<1, 2, 0>
 {
   public:
 
     MUnbox* mir() const { MOZ_CRASH(); }
     const LAllocation* payload() { MOZ_CRASH(); }