diff -r 91c993c1c4d0 js/src/jsatom.tbl
--- a/js/src/jsatom.tbl	Wed Aug 08 23:12:58 2012 +0200
+++ b/js/src/jsatom.tbl	Wed Aug 08 23:13:53 2012 +0200
@@ -39,16 +39,17 @@ DEFINE_ATOM(apply, "apply")
 DEFINE_ATOM(arguments, "arguments")
 DEFINE_ATOM(arity, "arity")
 DEFINE_ATOM(BYTES_PER_ELEMENT, "BYTES_PER_ELEMENT")
 DEFINE_ATOM(call, "call")
 DEFINE_ATOM(callee, "callee")
 DEFINE_ATOM(caller, "caller")
 DEFINE_ATOM(classPrototype, "prototype")
 DEFINE_ATOM(constructor, "constructor")
+DEFINE_ATOM(deleteProperty, "deleteProperty")
 DEFINE_ATOM(each, "each")
 DEFINE_ATOM(eval, "eval")
 DEFINE_ATOM(fileName, "fileName")
 DEFINE_ATOM(get, "get")
 DEFINE_ATOM(global, "global")
 DEFINE_ATOM(ignoreCase, "ignoreCase")
 DEFINE_ATOM(index, "index")
 DEFINE_ATOM(input, "input")
diff -r 91c993c1c4d0 js/src/jsproxy.cpp
--- a/js/src/jsproxy.cpp	Wed Aug 08 23:12:58 2012 +0200
+++ b/js/src/jsproxy.cpp	Wed Aug 08 23:13:53 2012 +0200
@@ -1714,23 +1714,77 @@ ScriptedDirectProxyHandler::getOwnProper
         ReportInvalidTrapResult(cx, proxy, ATOM(getOwnPropertyNames));
         return false;
     }
 
     /* Steps g to n are shared */
     return ArrayToIdVector(cx, proxy, target, trapResult, props, ATOM(getOwnPropertyNames));
 }
 
+/* [[Delete]](P, Throw) */
 bool
 ScriptedDirectProxyHandler::delete_(JSContext *cx, JSObject *proxy_, jsid id_, bool *bp)
 {
-    JS_NOT_REACHED("not yet implemented");
+    RootedObject proxy(cx, proxy_);
+    RootedId id(cx, id_);
+
+    /* step 1 */
+    RootedObject handler(cx, GetDirectProxyHandlerObject(proxy));
+
+    /* step 2 */
+    RootedObject target(cx, GetProxyTargetObject(proxy));
+
+    /* step 3 */
+    RootedValue trap(cx);
+    if (!GetTrap(cx, handler, ATOM(deleteProperty), &trap))
+        return false;
+
+    /* step 4 */
+    if (trap.isUndefined()) 
+        return DirectProxyHandler::delete_(cx, proxy_, id_, bp);
+
+    /* step 5 */
+    JSString *name = ToString(cx, IdToValue(id));
+    if (!name)
     return false;
+    Value argv[] = {
+        ObjectValue(*target),
+        StringValue(name)
+    };
+    RootedValue trapResult(cx);
+    if (!Invoke(cx, ObjectValue(*handler), trap, 2, argv, trapResult.address()))
+        return false;
+
+    /* step 6 */
+    JSBool success;
+    if (!JS_ValueToBoolean(cx, trapResult, &success))
+        return false;
+
+    /* step 7 */
+    if (success) {
+        bool sealed;
+        if (!IsSealed(cx, target, id, &sealed)) 
+            return false;
+        if (sealed) {
+            js_ReportValueError(cx, JSMSG_CANT_DELETE, JSDVG_IGNORE_STACK, IdToValue(id), NULL);
+            return false;
+        }
+
+        *bp = true;
+        return true;
+    }
+
+    /* step 8 */
+
+    // FIXME: API doesn't allow us to throw errors
+    *bp = false;
+    return true;
 }
 
+
 bool
 ScriptedDirectProxyHandler::enumerate(JSContext *cx, JSObject *proxy, AutoIdVector &props)
 {
     JS_NOT_REACHED("not yet implemented");
     return false;
 }
 
 bool