--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -214,16 +214,39 @@ Arena<T>::getAlignedThing(T *thing)
 
 #ifdef DEBUG
 template <typename T>
 bool
 Arena<T>::assureThingIsAligned(T *thing)
 {
     return (getAlignedThing(thing) == thing);
 }
+
+template
+bool
+Arena<JSObject>::assureThingIsAligned(JSObject *thing);
+
+template
+bool
+Arena<JSFunction>::assureThingIsAligned(JSFunction *thing);
+
+template
+bool
+Arena<JSString>::assureThingIsAligned(JSString *thing);
+
+template
+bool
+Arena<JSShortString>::assureThingIsAligned(JSShortString *thing);
+
+#if JS_HAS_XML_SUPPORT
+template
+bool
+Arena<JSXML>::assureThingIsAligned(JSXML *thing);
+#endif
+
 #endif
 
 template<typename T>
 inline ConservativeGCTest
 Arena<T>::mark(T *thing, JSTracer *trc)
 {
     thing = getAlignedThing(thing);