diff --git a/src/ZenWorkspaces.mjs b/src/ZenWorkspaces.mjs
index 1377f8b..77b8c7c 100644
--- a/src/ZenWorkspaces.mjs
+++ b/src/ZenWorkspaces.mjs
@@ -488,7 +488,7 @@ var ZenWorkspaces = {
     for (let workspace of workspaces.workspaces) {
       workspace.used = workspace.uuid === window.uuid;
     }
-    this.unsafeSaveWorkspaces(workspaces);
+    await this.unsafeSaveWorkspaces(workspaces);
     console.info('ZenWorkspaces: Changing workspace to', window.uuid);
     for (let i = 0; i < gBrowser.tabs.length; i++) {
       let tab = gBrowser.tabs[i];