diff --git a/content/treestyletab/treestyletabbrowser.js b/content/treestyletab/treestyletabbrowser.js
index 55516dc4..fee4e96e 100644
--- a/content/treestyletab/treestyletabbrowser.js
+++ b/content/treestyletab/treestyletabbrowser.js
@@ -460,7 +460,11 @@ TreeStyleTabBrowser.prototype = {
 
 		eval('b.warnAboutClosingTabs = '+
 			b.warnAboutClosingTabs.toSource().replace(
-				'var numTabs = ', 'var numTabs = this.__treestyletab__closedTabsNum || '
+				'var numTabs = ',
+				'var numTabs = this.__treestyletab__closedTabsNum || '
+			).replace(
+				'--tabsToClose',
+				'if (numTabs == this.mTabs.length) { $&; }'
 			)
 		);