diff --git a/kallithea/public/less/style.less b/kallithea/public/less/style.less
--- a/kallithea/public/less/style.less
+++ b/kallithea/public/less/style.less
@@ -86,6 +86,11 @@ nav.navbar.mainmenu .navbar-brand .brand
   min-height: 0.01%;
 }
 
+/* allow other exceptions to automatic overflow-x */
+.panel > .overflow-x-visible {
+  overflow-x: visible;
+}
+
 /* search highlighting */
 div.search-code-body pre .match {
   background-color: @highlight-color;
diff --git a/kallithea/templates/files/diff_2way.html b/kallithea/templates/files/diff_2way.html
--- a/kallithea/templates/files/diff_2way.html
+++ b/kallithea/templates/files/diff_2way.html
@@ -30,7 +30,7 @@ ${self.repo_context_bar('changelog')}
         ${self.breadcrumbs()}
     </div>
 
-    <div class="no-padding panel-body">
+    <div class="no-padding panel-body overflow-x-visible">
         <div class="panel panel-default">
             <div class="panel-heading clearfix">
                     <div class="pull-left">
@@ -56,7 +56,7 @@ ${self.repo_context_bar('changelog')}
                       ${h.checkbox('edit_mode', label=_('Edit'))}
                     </div>
             </div>
-            <div id="compare"></div>
+            <div id="compare" class="overflow-x-visible"></div>
         </div>
     </div>