diff --git a/src/js/background/backgroundLogic.js b/src/js/background/backgroundLogic.js
index 36bcb47..04906d8 100644
--- a/src/js/background/backgroundLogic.js
+++ b/src/js/background/backgroundLogic.js
@@ -131,9 +131,13 @@ const backgroundLogic = {
     let newWindowObj;
     let hiddenDefaultTabToClose;
     if (list.length) {
-      newWindowObj = await browser.windows.create({
-        tabId: list.shift().id
-      });
+      newWindowObj = await browser.windows.create();
+
+      // Pin the default tab in the new window so existing pinned tabs can be moved after it.
+      // From the docs (https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/tabs/move):
+      //   Note that you can't move pinned tabs to a position after any unpinned tabs in a window, or move any unpinned tabs to a position before any pinned tabs.
+      await browser.tabs.update(newWindowObj.tabs[0].id, { pinned: true });
+
       browser.tabs.move(list.map((tab) => tab.id), {
         windowId: newWindowObj.id,
         index: -1