diff --git a/js/src/asmjs/WasmIonCompile.cpp b/js/src/asmjs/WasmIonCompile.cpp
index 3bddcbf401c7..a08855f99f14 100644
--- a/js/src/asmjs/WasmIonCompile.cpp
+++ b/js/src/asmjs/WasmIonCompile.cpp
@@ -312,7 +312,7 @@ class FunctionCompiler
         return constant;
     }
 
-    MDefinition* constant(Value v, MIRType type)
+    MDefinition* constant(const Value& v, MIRType type)
     {
         if (inDeadCode())
             return nullptr;
diff --git a/js/src/jit/BaselineBailouts.cpp b/js/src/jit/BaselineBailouts.cpp
index b5869e9eb3e0..420e0a7c82be 100644
--- a/js/src/jit/BaselineBailouts.cpp
+++ b/js/src/jit/BaselineBailouts.cpp
@@ -232,7 +232,7 @@ struct BaselineStackBuilder
         return true;
     }
 
-    bool writeValue(Value val, const char* info) {
+    bool writeValue(const Value& val, const char* info) {
         if (!write<Value>(val))
             return false;
         if (info) {
diff --git a/js/src/jit/BaselineIC.cpp b/js/src/jit/BaselineIC.cpp
index ac35aef22b4e..5835283268d4 100644
--- a/js/src/jit/BaselineIC.cpp
+++ b/js/src/jit/BaselineIC.cpp
@@ -5613,7 +5613,7 @@ GetTemplateObjectForClassHook(JSContext* cx, JSNative hook, CallArgs& args,
 }
 
 static bool
-IsOptimizableCallStringSplit(Value callee, int argc, Value* args)
+IsOptimizableCallStringSplit(const Value& callee, int argc, Value* args)
 {
     if (argc != 2 || !args[0].isString() || !args[1].isString())
         return false;
diff --git a/js/src/jit/IonCaches.cpp b/js/src/jit/IonCaches.cpp
index 1088f1459385..cacfc7163a43 100644
--- a/js/src/jit/IonCaches.cpp
+++ b/js/src/jit/IonCaches.cpp
@@ -532,7 +532,7 @@ IsOptimizableArgumentsObjectForLength(JSObject* obj)
 }
 
 static bool
-IsOptimizableArgumentsObjectForGetElem(JSObject* obj, Value idval)
+IsOptimizableArgumentsObjectForGetElem(JSObject* obj, const Value& idval)
 {
     if (!IsOptimizableArgumentsObjectForLength(obj))
         return false;
diff --git a/js/src/jit/JitFrameIterator.h b/js/src/jit/JitFrameIterator.h
index 58c63fc19a9c..13990308e3be 100644
--- a/js/src/jit/JitFrameIterator.h
+++ b/js/src/jit/JitFrameIterator.h
@@ -378,7 +378,7 @@ struct MaybeReadFallback
         return UndefinedValue();
     }
 
-    NoGCValue noGCPlaceholder(Value v) const {
+    NoGCValue noGCPlaceholder(const Value& v) const {
         if (v.isMagic(JS_OPTIMIZED_OUT))
             return NoGC_MagicOptimizedOut;
         return NoGC_UndefinedValue;
@@ -445,7 +445,7 @@ class SnapshotIterator
 
     Value allocationValue(const RValueAllocation& a, ReadMethod rm = RM_Normal);
     MOZ_MUST_USE bool allocationReadable(const RValueAllocation& a, ReadMethod rm = RM_Normal);
-    void writeAllocationValuePayload(const RValueAllocation& a, Value v);
+    void writeAllocationValuePayload(const RValueAllocation& a, const Value& v);
     void warnUnreadableAllocation();
 
   private:
@@ -477,7 +477,7 @@ class SnapshotIterator
 
     // Used by recover instruction to store the value back into the instruction
     // results array.
-    void storeInstructionResult(Value v);
+    void storeInstructionResult(const Value& v);
 
   public:
     // Exhibits frame properties contained in the snapshot.
@@ -651,7 +651,7 @@ class InlineFrameIterator
 
   private:
     void findNextFrame();
-    JSObject* computeEnvironmentChain(Value envChainValue, MaybeReadFallback& fallback,
+    JSObject* computeEnvironmentChain(const Value& envChainValue, MaybeReadFallback& fallback,
                                       bool* hasInitialEnv = nullptr) const;
 
   public:
diff --git a/js/src/jit/JitFrames.cpp b/js/src/jit/JitFrames.cpp
index 5c6a3e80b2eb..feb24367499f 100644
--- a/js/src/jit/JitFrames.cpp
+++ b/js/src/jit/JitFrames.cpp
@@ -1926,7 +1926,7 @@ SnapshotIterator::maybeRead(const RValueAllocation& a, MaybeReadFallback& fallba
 }
 
 void
-SnapshotIterator::writeAllocationValuePayload(const RValueAllocation& alloc, Value v)
+SnapshotIterator::writeAllocationValuePayload(const RValueAllocation& alloc, const Value& v)
 {
     uintptr_t payload = *v.payloadUIntPtr();
 #if defined(JS_PUNBOX64)
@@ -2144,7 +2144,7 @@ SnapshotIterator::computeInstructionResults(JSContext* cx, RInstructionResults*
 }
 
 void
-SnapshotIterator::storeInstructionResult(Value v)
+SnapshotIterator::storeInstructionResult(const Value& v)
 {
     uint32_t currIns = recover_.numInstructionsRead() - 1;
     MOZ_ASSERT((*instructionResults_)[currIns].isMagic(JS_ION_BAILOUT));
@@ -2405,7 +2405,8 @@ InlineFrameIterator::callee(MaybeReadFallback& fallback) const
 }
 
 JSObject*
-InlineFrameIterator::computeEnvironmentChain(Value envChainValue, MaybeReadFallback& fallback,
+InlineFrameIterator::computeEnvironmentChain(const Value& envChainValue,
+                                             MaybeReadFallback& fallback,
                                              bool* hasInitialEnv) const
 {
     if (envChainValue.isObject()) {