diff --git a/app/assets/stylesheets/zammad.scss b/app/assets/stylesheets/zammad.scss
index 77f690c57..3ab10f4d1 100644
--- a/app/assets/stylesheets/zammad.scss
+++ b/app/assets/stylesheets/zammad.scss
@@ -5968,6 +5968,8 @@ footer {
 }
 
 .dropdown-menu {
+  @extend .zIndex-9; // has to be behind modal windows
+  position: absolute;
   margin: 0;
   padding: 0;
   min-width: 100%;