--- a/js/src/jstracer.cpp
+++ b/js/src/jstracer.cpp
@@ -4671,16 +4671,19 @@ TraceRecorder::record_JSOP_SETPROP()
     if (obj->map->ops->setProperty != js_SetProperty)
         ABORT_TRACE("non-native JSObjectOps::setProperty");
     return true;
 }
 
 bool
 TraceRecorder::record_SetPropHit(JSPropCacheEntry* entry, JSScopeProperty* sprop)
 {
+    if (sprop->setter == js_watch_set)
+        ABORT_TRACE("watchpoint detected");
+
     jsbytecode* pc = cx->fp->regs->pc;
     jsval& r = stackval(-1);
     jsval& l = stackval(-2);
 
     JS_ASSERT(!JSVAL_IS_PRIMITIVE(l));
     JSObject* obj = JSVAL_TO_OBJECT(l);
     LIns* obj_ins = get(&l);