diff --git a/components/script/dom/bindings/global.rs b/components/script/dom/bindings/global.rs
index 92b79e352e2..0cbb3ec302b 100644
--- a/components/script/dom/bindings/global.rs
+++ b/components/script/dom/bindings/global.rs
@@ -18,7 +18,7 @@ use js::{JSCLASS_IS_DOMJSCLASS, JSCLASS_IS_GLOBAL};
 use js::glue::{IsWrapper, UnwrapObject};
 use js::jsapi::{CurrentGlobalOrNull, GetGlobalForObjectCrossCompartment};
 use js::jsapi::{JSContext, JSObject, JS_GetClass};
-use script_runtime::{CommonScriptMsg, EnqueuedPromiseCallback, ScriptChan, ScriptPort};
+use script_runtime::{CommonScriptMsg, ScriptChan, ScriptPort};
 use script_thread::ScriptThread;
 use task_source::file_reading::FileReadingTaskSource;
 
@@ -84,14 +84,6 @@ impl<'a> GlobalRef<'a> {
             GlobalRef::Worker(ref worker) => worker.process_event(msg),
         }
     }
-
-    /// Enqueue a promise callback for subsequent execution.
-    pub fn enqueue_promise_job(&self, job: EnqueuedPromiseCallback) {
-        match *self {
-            GlobalRef::Window(_) => ScriptThread::enqueue_promise_job(job, *self),
-            GlobalRef::Worker(ref worker) => worker.enqueue_promise_job(job),
-        }
-    }
 }
 
 impl<'a> Reflectable for GlobalRef<'a> {
diff --git a/components/script/dom/globalscope.rs b/components/script/dom/globalscope.rs
index f9eaead2189..cd8fca9a0e4 100644
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@@ -26,7 +26,7 @@ use libc;
 use msg::constellation_msg::PipelineId;
 use net_traits::{CoreResourceThread, ResourceThreads, IpcSend};
 use profile_traits::{mem, time};
-use script_runtime::{ScriptChan, maybe_take_panic_result};
+use script_runtime::{EnqueuedPromiseCallback, ScriptChan, maybe_take_panic_result};
 use script_thread::{MainThreadScriptChan, RunnableWrapper, ScriptThread};
 use script_traits::{MsDuration, ScriptMsg as ConstellationMsg, TimerEvent};
 use script_traits::{TimerEventId, TimerEventRequest, TimerSource};
@@ -420,6 +420,17 @@ impl GlobalScope {
         }
         unreachable!();
     }
+
+    /// Enqueue a promise callback for subsequent execution.
+    pub fn enqueue_promise_job(&self, job: EnqueuedPromiseCallback) {
+        if self.is::<Window>() {
+            return ScriptThread::enqueue_promise_job(job, self);
+        }
+        if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
+            return worker.enqueue_promise_job(job);
+        }
+        unreachable!();
+    }
 }
 
 fn timestamp_in_ms(time: Timespec) -> u64 {
diff --git a/components/script/script_runtime.rs b/components/script/script_runtime.rs
index 36ae678ade7..145ef1ef19e 100644
--- a/components/script/script_runtime.rs
+++ b/components/script/script_runtime.rs
@@ -8,7 +8,7 @@
 use dom::bindings::callback::ExceptionHandling;
 use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::PromiseBinding::PromiseJobCallback;
-use dom::bindings::global::{global_root_from_object, GlobalRoot};
+use dom::bindings::global::{GlobalRoot, global_scope_from_object};
 use dom::bindings::js::{RootCollection, RootCollectionPtr, trace_roots};
 use dom::bindings::refcounted::{LiveDOMReferences, trace_refcounted_objects};
 use dom::bindings::trace::trace_traceables;
@@ -178,9 +178,9 @@ unsafe extern "C" fn enqueue_job(_cx: *mut JSContext,
                                  _allocation_site: HandleObject,
                                  _data: *mut c_void) -> bool {
     let result = panic::catch_unwind(AssertUnwindSafe(|| {
-        let global = global_root_from_object(job.get());
-        let pipeline = global.r().as_global_scope().pipeline_id();
-        global.r().enqueue_promise_job(EnqueuedPromiseCallback {
+        let global = global_scope_from_object(job.get());
+        let pipeline = global.pipeline_id();
+        global.enqueue_promise_job(EnqueuedPromiseCallback {
             callback: PromiseJobCallback::new(job.get()),
             pipeline: pipeline,
         });
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 467b77d1f76..22ca69c78df 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -27,7 +27,7 @@ use dom::bindings::codegen::Bindings::DocumentBinding::{DocumentMethods, Documen
 use dom::bindings::codegen::Bindings::LocationBinding::LocationMethods;
 use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use dom::bindings::conversions::{ConversionResult, FromJSValConvertible, StringificationBehavior};
-use dom::bindings::global::{GlobalRef, GlobalRoot};
+use dom::bindings::global::GlobalRoot;
 use dom::bindings::inheritance::Castable;
 use dom::bindings::js::{JS, MutNullableHeap, Root, RootCollection};
 use dom::bindings::js::{RootCollectionPtr, RootedReference};
@@ -2173,10 +2173,10 @@ impl ScriptThread {
         }
     }
 
-    pub fn enqueue_promise_job(job: EnqueuedPromiseCallback, global: GlobalRef) {
+    pub fn enqueue_promise_job(job: EnqueuedPromiseCallback, global: &GlobalScope) {
         SCRIPT_THREAD_ROOT.with(|root| {
             let script_thread = unsafe { &*root.get().unwrap() };
-            script_thread.promise_job_queue.enqueue(job, global.as_global_scope());
+            script_thread.promise_job_queue.enqueue(job, global);
         });
     }