diff --git a/chrome/content/zotero-platform/mac/preferences.css b/chrome/content/zotero-platform/mac/preferences.css
index 6b2a09c756..1f4170cf71 100644
--- a/chrome/content/zotero-platform/mac/preferences.css
+++ b/chrome/content/zotero-platform/mac/preferences.css
@@ -21,5 +21,6 @@ groupbox > label > h2, groupbox > * > label > h2, caption {
 
 .help-button {
 	appearance: auto;
-	-moz-default-appearance: -moz-mac-help-button;	
+	-moz-default-appearance: -moz-mac-help-button;
+	min-width: 0;
 }