diff --git a/client/src/sass/bootstrap.scss b/client/src/sass/bootstrap.scss
index e10b84596..6cced995e 100644
--- a/client/src/sass/bootstrap.scss
+++ b/client/src/sass/bootstrap.scss
@@ -22,11 +22,13 @@ $icon-font-path: '~@neos21/bootstrap3-glyphicons/assets/fonts/';
   }
 }
 
-.dropdown {
+/* rules for dropdowns excepts when in button group, to avoid impacting the dropdown-toggle */
+.dropdown:not(.btn-group) {
   z-index: z(dropdown) !important;
 }
 
 .dropdown-menu {
+  z-index: z(dropdown) !important;
   border-radius: 3px;
   box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 1px 5px 0 rgba(0, 0, 0, 0.12), 0 3px 1px -2px rgba(0, 0, 0, 0.2);
   font-size: 15px;
@@ -187,6 +189,14 @@ ngb-modal-window {
   z-index: z(modal) !important;
 }
 
+ngb-popover-window {
+  z-index: z(popover) !important;
+}
+
+ngb-tooltip-window {
+  z-index: z(tooltip) !important;
+}
+
 .btn-outline-tertiary {
   color: var(--secondaryColor);
   border-color: var(--secondaryColor);
diff --git a/client/src/sass/include/_bootstrap-variables.scss b/client/src/sass/include/_bootstrap-variables.scss
index b3ab0eb2b..d536eac86 100644
--- a/client/src/sass/include/_bootstrap-variables.scss
+++ b/client/src/sass/include/_bootstrap-variables.scss
@@ -1,6 +1,5 @@
 $dropdown-link-active-bg: inherit;
 
-$zindex-modal: 10005;
 $modal-footer-border-width: 0;
 $modal-md: 600px;
 
@@ -31,6 +30,3 @@ $input-focus-border-color: #ced4da;
 
 $nav-pills-link-active-bg: #F0F0F0;
 $nav-pills-link-active-color: #000;
-
-$zindex-dropdown: 10000;
-$zindex-popover: 10000;
diff --git a/client/src/sass/include/_variables.scss b/client/src/sass/include/_variables.scss
index 3fb8bb625..0c37cd68a 100644
--- a/client/src/sass/include/_variables.scss
+++ b/client/src/sass/include/_variables.scss
@@ -104,13 +104,15 @@ $variables: (
 $zindex: (
   header       :  1000,
   /* header context */
-  headerLeft :    10,
+  headerLeft   :    10,
   menu         : 11000,
   dropdown     : 12000,
-  loadbar      : 13000,
-  modal        : 14000,
-  notification : 15000,
-  hotkeys      : 16000
+  popover      : 13000,
+  tooltip      : 14000,
+  loadbar      : 15000,
+  modal        : 16000,
+  notification : 17000,
+  hotkeys      : 18000
 );
 
 @function z($label) {