--- a/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_network_messages_expand.js
+++ b/devtools/client/webconsole/new-console-output/test/mochitest/browser_webconsole_network_messages_expand.js
@@ -58,23 +58,22 @@ async function testNetworkMessage(messag
 
   // Headers tab should be selected by default, so just check its content.
   let headersContent = messageNode.querySelector(
     "#headers-panel .headers-overview");
   ok(headersContent, "Headers content is available");
 
   // Select Response tab and check the content. CodeMirror initialization
   // is delayed  to prevent UI freeze, so wait for a little while.
-  // TODO: Bug 1406100 - The 'responseContent' network event update is missing sometimes
-  /* responseTab.click();
+  responseTab.click();
   await waitForSourceEditor(messageNode);
   let responseContent = messageNode.querySelector(
     "#response-panel .editor-row-container .CodeMirror");
   ok(responseContent, "Response content is available");
-  ok(responseContent.textContent, "Response text is available"); */
+  ok(responseContent.textContent, "Response text is available");
 
   // Select Timings tab and check the content.
   timingsTab.click();
   let timingsContent = messageNode.querySelector(
     "#timings-panel .timings-container .timings-label");
   ok(timingsContent, "Timings content is available");
   ok(timingsContent.textContent, "Timings text is available");
 }
@@ -87,14 +86,14 @@ async function waitForNetworkUpdates(too
   return new Promise(resolve => {
     ui.jsterm.hud.on("network-request-payload-ready", () => {
       info("network-request-payload-ready received");
       resolve();
     });
   });
 }
 
-/* async function waitForSourceEditor(messageNode) {
+async function waitForSourceEditor(messageNode) {
   return waitUntil(() => {
     return !!messageNode.querySelector(
       "#response-panel .editor-row-container .CodeMirror");
   });
-} */
+}