--- a/testing/talos/talos/tests/devtools/addon/content/damp.js
+++ b/testing/talos/talos/tests/devtools/addon/content/damp.js
@@ -274,18 +274,23 @@ Damp.prototype = {
       let tab = this._win.gBrowser.selectedTab = this._win.gBrowser.addTab(url);
       let browser = tab.linkedBrowser;
       browser.addEventListener("load", function onload() {
         resolve(tab);
       }, {capture: true, once: true});
     });
   },
 
-  closeCurrentTab() {
+  async closeCurrentTab() {
+    let onTransition = new Promise(done => {
+      this._win.gBrowser.tabContainer.addEventListener("transitionend", done,
+        { once: true });
+    });
     this._win.BrowserCloseTabOrWindow();
+    await onTransition;
     return this._win.gBrowser.selectedTab;
   },
 
   reloadPage(onReload) {
     return new Promise(resolve => {
       let browser = gBrowser.selectedBrowser;
       if (typeof (onReload) == "function") {
         onReload().then(resolve);
@@ -903,17 +908,17 @@ async _consoleOpenWithCachedMessagesTest
     let tab = await this.addTab(url);
     await new Promise(resolve => {
       setTimeout(resolve, this._config.rest);
     });
     return tab;
   },
 
   async testTeardown(url) {
-    this.closeCurrentTab();
+    await this.closeCurrentTab();
 
     // Force freeing memory now so that it doesn't happen during the next test
     await garbageCollect();
 
     this._nextCommand();
   },
 
   // Everything below here are common pieces needed for the test runner to function,