diff --git a/js/src/jit/BaselineCompiler.cpp b/js/src/jit/BaselineCompiler.cpp
index f75b718706b4..efcef562f192 100644
--- a/js/src/jit/BaselineCompiler.cpp
+++ b/js/src/jit/BaselineCompiler.cpp
@@ -4047,9 +4047,11 @@ BaselineCompiler::emit_JSOP_TOID()
     frame.syncStack(0);
     masm.loadValue(frame.addressOfStackValue(frame.peek(-1)), R0);
 
-    // No-op if index is int32.
+    // No-op if the index is trivally convertable to an id.
     Label done;
     masm.branchTestInt32(Assembler::Equal, R0, &done);
+    masm.branchTestString(Assembler::Equal, R0, &done);
+    masm.branchTestSymbol(Assembler::Equal, R0, &done);
 
     prepareVMCall();
 
diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index 6fceb11066c0..576575d0cbc6 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -12477,8 +12477,9 @@ IonBuilder::jsop_toasynciter()
 AbortReasonOr<Ok>
 IonBuilder::jsop_toid()
 {
-    // No-op if the index is an integer.
-    if (current->peek(-1)->type() == MIRType::Int32)
+    // No-op if the index is trivally convertable to an id.
+    MIRType type = current->peek(-1)->type();
+    if (type == MIRType::Int32 || type == MIRType::String || type == MIRType::Symbol)
         return Ok();
 
     MDefinition* index = current->pop();
diff --git a/js/src/jit/IonIC.cpp b/js/src/jit/IonIC.cpp
index d71dbc7a7a43..d74fcb22a5cd 100644
--- a/js/src/jit/IonIC.cpp
+++ b/js/src/jit/IonIC.cpp
@@ -189,7 +189,7 @@ IonGetPropertyIC::update(JSContext* cx, HandleScript outerScript, IonGetProperty
 
 /* static */ bool
 IonSetPropertyIC::update(JSContext* cx, HandleScript outerScript, IonSetPropertyIC* ic,
-			 HandleObject obj, HandleValue idVal, HandleValue rhs)
+                         HandleObject obj, HandleValue idVal, HandleValue rhs)
 {
     RootedShape oldShape(cx);
     RootedObjectGroup oldGroup(cx);
@@ -225,6 +225,8 @@ IonSetPropertyIC::update(JSContext* cx, HandleScript outerScript, IonSetProperty
     }
 
     jsbytecode* pc = ic->pc();
+
+
     if (ic->kind() == CacheKind::SetElem) {
         if (IsPropertyInitOp(JSOp(*pc))) {
             if (!InitElemOperation(cx, pc, obj, idVal, rhs))
@@ -241,7 +243,12 @@ IonSetPropertyIC::update(JSContext* cx, HandleScript outerScript, IonSetProperty
             RootedScript script(cx, ic->script());
             MOZ_ASSERT(!script->hasNonSyntacticScope());
             InitGlobalLexicalOperation(cx, &cx->global()->lexicalEnvironment(), script, pc, rhs);
+        } else if (IsPropertyInitOp(JSOp(*pc))) {
+            RootedId id(cx, AtomToId(&idVal.toString()->asAtom()));
+            if (!InitPropertyOperation(cx, JSOp(*pc), obj, id, rhs))
+                return false;
         } else {
+            MOZ_ASSERT(IsPropertySetOp(JSOp(*pc)));
             RootedPropertyName name(cx, idVal.toString()->asAtom().asPropertyName());
             if (!SetProperty(cx, obj, name, rhs, ic->strict(), pc))
                 return false;
diff --git a/js/src/vm/Interpreter-inl.h b/js/src/vm/Interpreter-inl.h
index bce383995b8c..0d2f9c481419 100644
--- a/js/src/vm/Interpreter-inl.h
+++ b/js/src/vm/Interpreter-inl.h
@@ -649,7 +649,7 @@ InitElemOperation(JSContext* cx, jsbytecode* pc, HandleObject obj, HandleValue i
     if (!ToPropertyKey(cx, idval, &id))
         return false;
 
-    unsigned flags = JSOp(*pc) == JSOP_INITHIDDENELEM ? 0 : JSPROP_ENUMERATE;
+    unsigned flags = GetInitDataPropAttrs(JSOp(*pc));
     return DefineProperty(cx, obj, id, val, nullptr, nullptr, flags);
 }
 
diff --git a/js/src/vm/Interpreter.cpp b/js/src/vm/Interpreter.cpp
index 01effb5d6780..44560c91a997 100644
--- a/js/src/vm/Interpreter.cpp
+++ b/js/src/vm/Interpreter.cpp
@@ -4761,10 +4761,12 @@ js::GetInitDataPropAttrs(JSOp op)
 {
     switch (op) {
       case JSOP_INITPROP:
+      case JSOP_INITELEM:
         return JSPROP_ENUMERATE;
       case JSOP_INITLOCKEDPROP:
         return JSPROP_PERMANENT | JSPROP_READONLY;
       case JSOP_INITHIDDENPROP:
+      case JSOP_INITHIDDENELEM:
         // Non-enumerable, but writable and configurable
         return 0;
       default:;