diff --git a/mozilla/js/src/jsdbgapi.c b/mozilla/js/src/jsdbgapi.c
index b8fd4ff9725..1fc63ad8872 100644
--- a/mozilla/js/src/jsdbgapi.c
+++ b/mozilla/js/src/jsdbgapi.c
@@ -279,14 +279,18 @@ DropWatchPoint(JSContext *cx, JSWatchPoint *wp)
 }
 
 void
-js_MarkWatchPoints(JSRuntime *rt)
+js_MarkWatchPoints(JSContext *cx)
 {
+    JSRuntime *rt;
     JSWatchPoint *wp;
 
+    rt = cx->runtime;
     for (wp = (JSWatchPoint *)rt->watchPointList.next;
          wp != (JSWatchPoint *)&rt->watchPointList;
          wp = (JSWatchPoint *)wp->links.next) {
         MARK_SCOPE_PROPERTY(wp->sprop);
+        if (wp->sprop->attrs & JSPROP_SETTER)
+            JS_MarkGCThing(cx, wp->setter, "wp->setter", NULL);
     }
 }
 
diff --git a/mozilla/js/src/jsdbgapi.h b/mozilla/js/src/jsdbgapi.h
index dea0f48cc39..d2e1f1c69ec 100644
--- a/mozilla/js/src/jsdbgapi.h
+++ b/mozilla/js/src/jsdbgapi.h
@@ -99,7 +99,7 @@ JS_ClearAllWatchPoints(JSContext *cx);
  * header file "jsconfig.h" has been included.
  */
 extern void
-js_MarkWatchPoints(JSRuntime *rt);
+js_MarkWatchPoints(JSContext *cx);
 
 extern JSScopeProperty *
 js_FindWatchPoint(JSRuntime *rt, JSScope *scope, jsid id);
diff --git a/mozilla/js/src/jsgc.c b/mozilla/js/src/jsgc.c
index 1d5a0393dfa..f3d7a30872c 100644
--- a/mozilla/js/src/jsgc.c
+++ b/mozilla/js/src/jsgc.c
@@ -2745,7 +2745,7 @@ restart:
     if (rt->gcLocksHash)
         JS_DHashTableEnumerate(rt->gcLocksHash, gc_lock_marker, cx);
     js_MarkAtomState(&rt->atomState, keepAtoms, gc_mark_atom_key_thing, cx);
-    js_MarkWatchPoints(rt);
+    js_MarkWatchPoints(cx);
     js_MarkScriptFilenames(rt, keepAtoms);
     js_MarkNativeIteratorStates(cx);