diff --git a/content/treestyletab/treestyletabbrowser.js b/content/treestyletab/treestyletabbrowser.js
index 8353f33a..813ac7e5 100644
--- a/content/treestyletab/treestyletabbrowser.js
+++ b/content/treestyletab/treestyletabbrowser.js
@@ -1244,7 +1244,9 @@ TreeStyleTabBrowser.prototype = {
 			this.mTabBrowser.getAttribute(this.kFIXED) != 'true') {
 			strip.setAttribute('layer', true); // https://bugzilla.mozilla.org/show_bug.cgi?id=590468
 
-			if (this.autoHide.expanded && (aReason & this.kTABBAR_UPDATE_SYNC_TO_PLACEHOLDER))
+			if (this.autoHide.expanded &&
+				(aReason & this.kTABBAR_UPDATE_SYNC_TO_PLACEHOLDER) &&
+				this.autoHide.mode == this.autoHide.kMODE_SHRINK)
 				this.autoHide.hide();
 
 			let box = this._tabStripPlaceHolder.boxObject;