--- a/browser/components/extensions/ext-tabs.js
+++ b/browser/components/extensions/ext-tabs.js
@@ -612,16 +612,22 @@ this.tabs = class extends ExtensionAPI {
           let lastInsertion = new Map();
 
           let tabs = tabIds.map(tabId => tabTracker.getTab(tabId));
           for (let nativeTab of tabs) {
             // If the window is not specified, use the window from the tab.
             let window = destinationWindow || nativeTab.ownerGlobal;
             let gBrowser = window.gBrowser;
 
+            // If we are not moving the tab to a different window, and the window
+            // only has one tab, do nothing.
+            if (nativeTab.ownerGlobal == window && gBrowser.tabs.length === 1) {
+              continue;
+            }
+
             let insertionPoint = indexMap.get(window) || moveProperties.index;
             // If the index is -1 it should go to the end of the tabs.
             if (insertionPoint == -1) {
               insertionPoint = gBrowser.tabs.length;
             }
 
             // We can only move pinned tabs to a point within, or just after,
             // the current set of pinned tabs. Unpinned tabs, likewise, can only