diff --git a/widget/GfxInfoBase.cpp b/widget/GfxInfoBase.cpp
index cf3e28b9570..8625ba228a6 100644
--- a/widget/GfxInfoBase.cpp
+++ b/widget/GfxInfoBase.cpp
@@ -1163,20 +1163,6 @@ GfxInfoBase::RemoveCollector(GfxInfoCollectorBase* collector)
   }
 }
 
-NS_IMETHODIMP
-GfxInfoBase::GetMonitors(JSContext* aCx, JS::MutableHandleValue aResult)
-{
-  JS::Rooted<JSObject*> array(aCx, JS_NewArrayObject(aCx, 0));
-
-  nsresult rv = FindMonitors(aCx, array);
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  aResult.setObject(*array);
-  return NS_OK;
-}
-
 GfxInfoCollectorBase::GfxInfoCollectorBase()
 {
   GfxInfoBase::AddCollector(this);
diff --git a/widget/GfxInfoBase.h b/widget/GfxInfoBase.h
index 2a87e19c31d..6b539f234dc 100644
--- a/widget/GfxInfoBase.h
+++ b/widget/GfxInfoBase.h
@@ -54,8 +54,7 @@ public:
   NS_IMETHOD GetFeatureSuggestedDriverVersion(int32_t aFeature, nsAString & _retval) override;
   NS_IMETHOD GetWebGLParameter(const nsAString & aParam, nsAString & _retval) override;
 
-  NS_IMETHOD GetMonitors(JSContext* cx, JS::MutableHandleValue _retval) override;
-  NS_IMETHOD GetFailures(uint32_t *failureCount, int32_t** indices, char ***failures) override;
+    NS_IMETHOD GetFailures(uint32_t *failureCount, int32_t** indices, char ***failures) override;
   NS_IMETHOD_(void) LogFailure(const nsACString &failure) override;
   NS_IMETHOD GetInfo(JSContext*, JS::MutableHandle<JS::Value>) override;
 
diff --git a/widget/nsIGfxInfo.idl b/widget/nsIGfxInfo.idl
index 8b10556b2fa..fde9e6b27ff 100644
--- a/widget/nsIGfxInfo.idl
+++ b/widget/nsIGfxInfo.idl
@@ -8,7 +8,7 @@
 
 /* NOTE: this interface is completely undesigned, not stable and likely to change */
 
-[scriptable, uuid(47eedfa0-f7cb-445b-b5cf-a2ca83600560)]
+[scriptable, uuid(b0cd9d34-8dba-4b1d-8126-ca21826dbf35)]
 interface nsIGfxInfo : nsISupports
 {
   /*
@@ -54,17 +54,6 @@ interface nsIGfxInfo : nsISupports
 
   readonly attribute boolean isGPU2Active;
 
-  /**
-   * Returns an array of objects describing each monitor. Guaranteed properties
-   * are "screenWidth" and "screenHeight". This is only implemented on Desktop.
-   *
-   * Windows additionally supplies "refreshRate" and "pseudoDisplay".
-   *
-   * OS X additionally supplies "scale".
-   */
-  [implicit_jscontext]
-  jsval getMonitors();
-
   void getFailures(
                out unsigned long failureCount,
                [optional, array, size_is(failureCount)] out long indices,