diff --git a/content/xbl/src/nsXBLProtoImplField.cpp b/content/xbl/src/nsXBLProtoImplField.cpp
index 7085d818856..30745378656 100644
--- a/content/xbl/src/nsXBLProtoImplField.cpp
+++ b/content/xbl/src/nsXBLProtoImplField.cpp
@@ -327,7 +327,7 @@ nsXBLProtoImplField::InstallAccessors(JSContext* aCx,
   // Get the field name as an id.
   JS::Rooted<jsid> id(aCx);
   JS::TwoByteChars chars(mName, NS_strlen(mName));
-  if (!JS_CharsToId(aCx, chars, id.address()))
+  if (!JS_CharsToId(aCx, chars, &id))
     return NS_ERROR_OUT_OF_MEMORY;
 
   // Properties/Methods have historically taken precendence over fields. We
diff --git a/dom/indexedDB/KeyPath.cpp b/dom/indexedDB/KeyPath.cpp
index ff574de913d..67900cbcb63 100644
--- a/dom/indexedDB/KeyPath.cpp
+++ b/dom/indexedDB/KeyPath.cpp
@@ -46,8 +46,8 @@ IsValidKeyPathString(JSContext* aCx, const nsAString& aKeyPath)
       return false;
     }
 
-    NS_ASSERTION(JSVAL_IS_STRING(stringVal), "This should never happen");
-    JSString* str = JSVAL_TO_STRING(stringVal);
+    NS_ASSERTION(stringVal.toString(), "This should never happen");
+    JS::RootedString str(aCx, stringVal.toString());
 
     bool isIdentifier = false;
     if (!JS_IsIdentifier(aCx, str, &isIdentifier) || !isIdentifier) {
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 82e2520abbc..66db0991288 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -6126,17 +6126,13 @@ BOOL WINAPI DllMain (HINSTANCE hDLL, DWORD dwReason, LPVOID lpReserved)
 #endif
 
 JS_PUBLIC_API(bool)
-JS_IndexToId(JSContext *cx, uint32_t index, jsid *idp)
+JS_IndexToId(JSContext *cx, uint32_t index, MutableHandleId id)
 {
-    RootedId id(cx);
-    if (!IndexToId(cx, index, &id))
-        return false;
-    *idp = id;
-    return true;
+    return IndexToId(cx, index, id);
 }
 
 JS_PUBLIC_API(bool)
-JS_CharsToId(JSContext* cx, JS::TwoByteChars chars, jsid *idp)
+JS_CharsToId(JSContext* cx, JS::TwoByteChars chars, MutableHandleId idp)
 {
     RootedAtom atom(cx, AtomizeChars<CanGC>(cx, chars.start().get(), chars.length()));
     if (!atom)
@@ -6145,12 +6141,12 @@ JS_CharsToId(JSContext* cx, JS::TwoByteChars chars, jsid *idp)
     uint32_t dummy;
     MOZ_ASSERT(!atom->isIndex(&dummy), "API misuse: |chars| must not encode an index");
 #endif
-    *idp = AtomToId(atom);
+    idp.set(AtomToId(atom));
     return true;
 }
 
 JS_PUBLIC_API(bool)
-JS_IsIdentifier(JSContext *cx, JSString *str, bool *isIdentifier)
+JS_IsIdentifier(JSContext *cx, HandleString str, bool *isIdentifier)
 {
     assertSameCompartment(cx, str);
 
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 7b5a7587f42..680979685c9 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -4273,7 +4273,7 @@ JS_SetGlobalJitCompilerOption(JSContext *cx, JSJitCompilerOption opt, uint32_t v
  * Convert a uint32_t index into a jsid.
  */
 extern JS_PUBLIC_API(bool)
-JS_IndexToId(JSContext *cx, uint32_t index, jsid *id);
+JS_IndexToId(JSContext *cx, uint32_t index, JS::MutableHandleId);
 
 /*
  * Convert chars into a jsid.
@@ -4281,13 +4281,13 @@ JS_IndexToId(JSContext *cx, uint32_t index, jsid *id);
  * |chars| may not be an index.
  */
 extern JS_PUBLIC_API(bool)
-JS_CharsToId(JSContext* cx, JS::TwoByteChars chars, jsid *idp);
+JS_CharsToId(JSContext* cx, JS::TwoByteChars chars, JS::MutableHandleId);
 
 /*
  *  Test if the given string is a valid ECMAScript identifier
  */
 extern JS_PUBLIC_API(bool)
-JS_IsIdentifier(JSContext *cx, JSString *str, bool *isIdentifier);
+JS_IsIdentifier(JSContext *cx, JS::HandleString str, bool *isIdentifier);
 
 /*
  * Return the current script and line number of the most currently running