diff --git a/chrome/content/zotero/zoteroPane.xhtml b/chrome/content/zotero/zoteroPane.xhtml
index e898bf38ed..ef314b3ddc 100644
--- a/chrome/content/zotero/zoteroPane.xhtml
+++ b/chrome/content/zotero/zoteroPane.xhtml
@@ -1286,7 +1286,7 @@
 				<stack id="zotero-pane-overlay" flex="1" hidden="true">
 					<box style="background: black; opacity: .3" flex="1"/>
 					
-					<deck id="zotero-pane-overlay-deck" flex="1">
+					<deck id="zotero-pane-overlay-deck" style="display: flex; justify-content: center;">
 						<box id="zotero-pane-progress" flex="1" align="center" pack="center">
 							<box style="background: white; border-radius: 1px; box-shadow: gray 4px 6px 4px;" width="300" height="30">
 								<vbox id="zotero-pane-progressmeter-container" style="padding:10px" flex="1">