diff --git a/src/duk_js_executor.c b/src/duk_js_executor.c
index b52520e3..e0ce97ac 100644
--- a/src/duk_js_executor.c
+++ b/src/duk_js_executor.c
@@ -712,7 +712,7 @@ static int handle_longjmp(duk_hthread *thr,
 		DUK_ASSERT(thr->callstack_top >= 2);                                                                         /* Ecmascript activation + __duk__.resume() activation */
 		DUK_ASSERT((thr->callstack + thr->callstack_top - 1)->func != NULL &&
 		           DUK_HOBJECT_IS_NATIVEFUNCTION((thr->callstack + thr->callstack_top - 1)->func) &&
-		           ((duk_hnativefunction *) (thr->callstack + thr->callstack_top - 1)->func)->func == duk_builtin_duk_object_resume);
+		           ((duk_hnativefunction *) (thr->callstack + thr->callstack_top - 1)->func)->func == duk_builtin_thread_resume);
 		DUK_ASSERT((thr->callstack + thr->callstack_top - 2)->func != NULL &&
 		           DUK_HOBJECT_IS_COMPILEDFUNCTION((thr->callstack + thr->callstack_top - 2)->func));                /* an Ecmascript function */
 		DUK_ASSERT((thr->callstack + thr->callstack_top - 2)->idx_retval >= 0);                                      /* waiting for a value */
@@ -732,7 +732,7 @@ static int handle_longjmp(duk_hthread *thr,
 		DUK_ASSERT(resumee->state != DUK_HTHREAD_STATE_YIELDED ||
 		           ((resumee->callstack + resumee->callstack_top - 1)->func != NULL &&
 		            DUK_HOBJECT_IS_NATIVEFUNCTION((resumee->callstack + resumee->callstack_top - 1)->func) &&
-		            ((duk_hnativefunction *) (resumee->callstack + resumee->callstack_top - 1)->func)->func == duk_builtin_duk_object_yield));
+		            ((duk_hnativefunction *) (resumee->callstack + resumee->callstack_top - 1)->func)->func == duk_builtin_thread_yield));
 		DUK_ASSERT(resumee->state != DUK_HTHREAD_STATE_YIELDED ||
 		           ((resumee->callstack + resumee->callstack_top - 2)->func != NULL &&
 		            DUK_HOBJECT_IS_COMPILEDFUNCTION((resumee->callstack + resumee->callstack_top - 2)->func)));      /* an Ecmascript function */
@@ -851,7 +851,7 @@ static int handle_longjmp(duk_hthread *thr,
 		DUK_ASSERT(thr->callstack_top >= 2);                                                                         /* Ecmascript activation + __duk__.yield() activation */
 		DUK_ASSERT((thr->callstack + thr->callstack_top - 1)->func != NULL &&
 		           DUK_HOBJECT_IS_NATIVEFUNCTION((thr->callstack + thr->callstack_top - 1)->func) &&
-		           ((duk_hnativefunction *) (thr->callstack + thr->callstack_top - 1)->func)->func == duk_builtin_duk_object_yield);
+		           ((duk_hnativefunction *) (thr->callstack + thr->callstack_top - 1)->func)->func == duk_builtin_thread_yield);
 		DUK_ASSERT((thr->callstack + thr->callstack_top - 2)->func != NULL &&
 		           DUK_HOBJECT_IS_COMPILEDFUNCTION((thr->callstack + thr->callstack_top - 2)->func));                /* an Ecmascript function */
 		DUK_ASSERT((thr->callstack + thr->callstack_top - 2)->idx_retval >= 0);                                      /* waiting for a value */
@@ -863,7 +863,7 @@ static int handle_longjmp(duk_hthread *thr,
 		DUK_ASSERT(resumer->callstack_top >= 2);                                                                     /* Ecmascript activation + __duk__.resume() activation */
 		DUK_ASSERT((resumer->callstack + resumer->callstack_top - 1)->func != NULL &&
 		           DUK_HOBJECT_IS_NATIVEFUNCTION((resumer->callstack + resumer->callstack_top - 1)->func) &&
-		           ((duk_hnativefunction *) (resumer->callstack + resumer->callstack_top - 1)->func)->func == duk_builtin_duk_object_resume);
+		           ((duk_hnativefunction *) (resumer->callstack + resumer->callstack_top - 1)->func)->func == duk_builtin_thread_resume);
 		DUK_ASSERT((resumer->callstack + resumer->callstack_top - 2)->func != NULL &&
 		           DUK_HOBJECT_IS_COMPILEDFUNCTION((resumer->callstack + resumer->callstack_top - 2)->func));        /* an Ecmascript function */
 		DUK_ASSERT((resumer->callstack + resumer->callstack_top - 2)->idx_retval >= 0);                              /* waiting for a value */
@@ -1003,7 +1003,7 @@ static int handle_longjmp(duk_hthread *thr,
 		DUK_ASSERT(thr->resumer->callstack_top >= 2);  /* Ecmascript activation + __duk__.resume() activation */
 		DUK_ASSERT((thr->resumer->callstack + thr->resumer->callstack_top - 1)->func != NULL &&
 		           DUK_HOBJECT_IS_NATIVEFUNCTION((thr->resumer->callstack + thr->resumer->callstack_top - 1)->func) &&
-		           ((duk_hnativefunction *) (thr->resumer->callstack + thr->resumer->callstack_top - 1)->func)->func == duk_builtin_duk_object_resume);  /* __duk__.resume() */
+		           ((duk_hnativefunction *) (thr->resumer->callstack + thr->resumer->callstack_top - 1)->func)->func == duk_builtin_thread_resume);  /* __duk__.resume() */
 		DUK_ASSERT((thr->resumer->callstack + thr->resumer->callstack_top - 2)->func != NULL &&
 		           DUK_HOBJECT_IS_COMPILEDFUNCTION((thr->resumer->callstack + thr->resumer->callstack_top - 2)->func));  /* an Ecmascript function */
 		DUK_ASSERT((thr->resumer->callstack + thr->resumer->callstack_top - 2)->idx_retval >= 0);                        /* waiting for a value */
@@ -1178,7 +1178,7 @@ static int handle_longjmp(duk_hthread *thr,
 		DUK_ASSERT(thr->resumer->callstack_top >= 2);  /* Ecmascript activation + __duk__.resume() activation */
 		DUK_ASSERT((thr->resumer->callstack + thr->resumer->callstack_top - 1)->func != NULL &&
 		           DUK_HOBJECT_IS_NATIVEFUNCTION((thr->resumer->callstack + thr->resumer->callstack_top - 1)->func) &&
-		           ((duk_hnativefunction *) (thr->resumer->callstack + thr->resumer->callstack_top - 1)->func)->func == duk_builtin_duk_object_resume);  /* __duk__.resume() */
+		           ((duk_hnativefunction *) (thr->resumer->callstack + thr->resumer->callstack_top - 1)->func)->func == duk_builtin_thread_resume);  /* __duk__.resume() */
 		DUK_ASSERT((thr->resumer->callstack + thr->resumer->callstack_top - 2)->func != NULL &&
 		           DUK_HOBJECT_IS_COMPILEDFUNCTION((thr->resumer->callstack + thr->resumer->callstack_top - 2)->func));  /* an Ecmascript function */