diff --git a/modules/browser.js b/modules/browser.js
index c4262884..81efc649 100644
--- a/modules/browser.js
+++ b/modules/browser.js
@@ -1820,17 +1820,19 @@ TreeStyleTabBrowser.prototype = {
 		var splitter = this.splitter;
 		if (splitter.collapsed || splitter.getAttribute('state') != 'collapsed') {
 			let shouldAutoHideForSingleTab = (
+			(
 				// "autohide for single tab" feature is removed on Firefox 23.
 				// https://bugzilla.mozilla.org/show_bug.cgi?id=855370
 				(
 					prefs.getDefaultPref('browser.tabs.autoHide') !== null ||
 					// but "Hide Tab Bar With One Tab" provides it.
 					// https://addons.mozilla.org/firefox/addon/hide-tab-bar-with-one-tab/
-					'hideTabBar' in this.window ||
-					// Tab Mix Plus also provides it.
-					'TabmixTabbar' in this.window && this.window.TabmixTabbar.hideMode > 0
+					'hideTabBar' in this.window
 				) &&
 				prefs.getPref('browser.tabs.autoHide')
+			) ||
+			// Tab Mix Plus also provides it.
+			'TabmixTabbar' in this.window && this.window.TabmixTabbar.hideMode > 0
 			);
 			this._tabStripPlaceHolder.collapsed =
 				splitter.collapsed =