diff --git a/remote/domains/content/Runtime.jsm b/remote/domains/content/Runtime.jsm
index 0c079df7a71a..e3534a9ed6f8 100644
--- a/remote/domains/content/Runtime.jsm
+++ b/remote/domains/content/Runtime.jsm
@@ -7,6 +7,7 @@
 var EXPORTED_SYMBOLS = ["Runtime"];
 
 const {ContentProcessDomain} = ChromeUtils.import("chrome://remote/content/domains/ContentProcessDomain.jsm");
+const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 class Runtime extends ContentProcessDomain {
   constructor(session) {
@@ -25,6 +26,22 @@ class Runtime extends ContentProcessDomain {
       this.enabled = true;
       this.chromeEventHandler.addEventListener("DOMWindowCreated", this,
         {mozSystemGroup: true});
+
+      // Spin the event loop in order to send the `executionContextCreated` event right
+      // after we replied to `enable` request.
+      Services.tm.dispatchToMainThread(() => {
+        const frameId = this.content.windowUtils.outerWindowID;
+        const id = this.content.windowUtils.currentInnerWindowID;
+        this.emit("Runtime.executionContextCreated", {
+          context: {
+            id,
+            auxData: {
+              isDefault: true,
+              frameId,
+            },
+          },
+        });
+      });
     }
   }
 
diff --git a/remote/test/browser/browser_runtime_executionContext.js b/remote/test/browser/browser_runtime_executionContext.js
index 37cbf81f58ff..152dd6e0ce32 100644
--- a/remote/test/browser/browser_runtime_executionContext.js
+++ b/remote/test/browser/browser_runtime_executionContext.js
@@ -53,17 +53,24 @@ async function testCDP() {
   await Runtime.enable();
   ok(true, "Runtime domain has been enabled");
 
+  // Calling Runtime.enable will emit executionContextCreated for the existing contexts
+  const { context: context1 } = await Runtime.executionContextCreated();
+  ok(!!context1.id, "The execution context has an id");
+  ok(context1.auxData.isDefault, "The execution context is the default one");
+  ok(!!context1.auxData.frameId, "The execution context has a frame id set");
+
   const executionContextCreated = Runtime.executionContextCreated();
 
   const url = "data:text/html;charset=utf-8,test-page";
-  const { frameId } = await Page.navigate({ url  });
+  const { frameId } = await Page.navigate({ url });
   ok(true, "A new page has been loaded");
-  ok(frameId, "Page.navigate returned a frameId");
+  is(frameId, context1.auxData.frameId, "Page.navigate returns the same frameId than executionContextCreated");
 
-  const { context } = await executionContextCreated;
-  ok(!!context.id, "The execution context has an id");
-  ok(context.auxData.isDefault, "The execution context is the default one");
-  is(context.auxData.frameId, frameId, "The execution context frame id is the same " +
+  const { context: context2 } = await executionContextCreated;
+  ok(!!context2.id, "The execution context has an id");
+  isnot(context1.id, context2.id, "The new execution context has a different id");
+  ok(context2.auxData.isDefault, "The execution context is the default one");
+  is(context2.auxData.frameId, frameId, "The execution context frame id is the same " +
     "the one returned by Page.navigate");
 
   await client.close();