diff --git a/extensions/help/resources/skin/classic/help.css b/extensions/help/resources/skin/classic/help.css
index b88d092b67cd..feb200c94191 100644
--- a/extensions/help/resources/skin/classic/help.css
+++ b/extensions/help/resources/skin/classic/help.css
@@ -105,3 +105,7 @@
 #helpHomeButton:hover:active {
   list-style-image: url("chrome://communicator/skin/bookmarks/home-active.gif");
 }
+
+#helpsidebar-box {
+  min-width: 18em;
+}
diff --git a/extensions/help/resources/skin/modern/help.css b/extensions/help/resources/skin/modern/help.css
index 87f9cf06719f..e5d0598e896e 100644
--- a/extensions/help/resources/skin/modern/help.css
+++ b/extensions/help/resources/skin/modern/help.css
@@ -138,3 +138,7 @@
 #print[disabled="true"] {
   -moz-image-region: rect(0, 199px, 33px, 150px) !important;
 }
+
+#helpsidebar-box {
+  min-width: 18em;
+}