diff --git a/chrome/content/zotero/zoteroPane.xul b/chrome/content/zotero/zoteroPane.xul
index a6e41773ef..b96d52bdcb 100644
--- a/chrome/content/zotero/zoteroPane.xul
+++ b/chrome/content/zotero/zoteroPane.xul
@@ -287,7 +287,7 @@
 			
 			
 			<hbox id="zotero-trees" flex="1">
-				<vbox id="zotero-collections-pane" zotero-persist="width" flex="1">
+				<vbox id="zotero-collections-pane" zotero-persist="width">
 					<!-- This extra vbox prevents the toolbar from getting compressed when resizing
 							the tag selector to max height -->
 					<tree id="zotero-collections-tree" hidecolumnpicker="true" context="zotero-collectionmenu"