diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index b9cd7bd9ae2..507a7b78874 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -905,7 +905,7 @@ struct JSTracer {
  * The method to call on each reference to a traceable thing storted in a
  * particular JSObject or other runtime structure. With DEBUG defined the
  * caller before calling JS_CallTracer must initialize JSTracer fields
- * describing the reference using the macros bellow.
+ * describing the reference using the macros below.
  */
 extern JS_PUBLIC_API(void)
 JS_CallTracer(JSTracer *trc, void *thing, uint32 kind);
@@ -1183,7 +1183,7 @@ struct JSExtendedClass {
 #define JSCLASS_IS_ANONYMOUS            (1<<(JSCLASS_HIGH_FLAGS_SHIFT+1))
 #define JSCLASS_IS_GLOBAL               (1<<(JSCLASS_HIGH_FLAGS_SHIFT+2))
 
-/* Idicates that JSClass.mark is a tracer with JSTraceOp type. */
+/* Indicates that JSClass.mark is a tracer with JSTraceOp type. */
 #define JSCLASS_MARK_IS_TRACE           (1<<(JSCLASS_HIGH_FLAGS_SHIFT+3))
 
 /*
diff --git a/js/src/jspubtd.h b/js/src/jspubtd.h
index 8ee1e428af1..98b7c669c93 100644
--- a/js/src/jspubtd.h
+++ b/js/src/jspubtd.h
@@ -356,19 +356,19 @@ typedef uint32
  *
  * To define the tracer for a JSClass, the implementation must add
  * JSCLASS_MARK_IS_TRACE to class flags and use JS_CLASS_TRACE(method)
- * macro bellow to convert JSTraceOp to JSMarkOp when initializing or
+ * macro below to convert JSTraceOp to JSMarkOp when initializing or
  * assigning JSClass.mark field.
  */
 typedef void
 (* JS_DLL_CALLBACK JSTraceOp)(JSTracer *trc, JSObject *obj);
 
-#if defined __GNUC__ && __GNUC__ >= 4
+#if defined __GNUC__ && __GNUC__ >= 4 && !defined __cplusplus
 # define JS_CLASS_TRACE(method)                                               \
-    (__builtin_types_compatible_p(JSTraceOp, __typeof(&method))               \
+    (__builtin_types_compatible_p(JSTraceOp, __typeof(&(method)))             \
      ? (JSMarkOp)(method)                                                     \
-     : JS_WrongTypeForClassTacer)
+     : js_WrongTypeForClassTracer)
 
-extern JSMarkOp JS_WrongTypeForClassTacer;
+extern JSMarkOp js_WrongTypeForClassTracer;
 
 #else
 # define JS_CLASS_TRACE(method) ((JSMarkOp)(method))