diff --git a/themes/original/css/theme_right.css.php b/themes/original/css/theme_right.css.php
index e7bbe41c91..dc134d73c5 100644
--- a/themes/original/css/theme_right.css.php
+++ b/themes/original/css/theme_right.css.php
@@ -678,6 +678,7 @@ ul#topmenu ul {
     list-style-type:    none;
     display:            none;
     border:             1px #666 solid;
+    z-index:            2;
 }
 
 ul#topmenu li:hover ul, ul#topmenu .submenuhover ul {
diff --git a/themes/pmahomme/css/theme_right.css.php b/themes/pmahomme/css/theme_right.css.php
index 7209b60337..dd2c9ef263 100644
--- a/themes/pmahomme/css/theme_right.css.php
+++ b/themes/pmahomme/css/theme_right.css.php
@@ -861,6 +861,7 @@ ul#topmenu ul {
     list-style-type:    none;
     display:            none;
     border:             1px #ddd solid;
+    z-index:            2;
 }
 
 ul#topmenu li:hover {