--- a/devtools/client/netmonitor/src/assets/styles/RequestList.css
+++ b/devtools/client/netmonitor/src/assets/styles/RequestList.css
@@ -95,17 +95,17 @@
   padding: 1px;
 }
 
 /* Requests list headers */
 
 .requests-list-headers-wrapper {
   position: sticky;
   top: 0;
-  z-index: 1000;
+  z-index: 1;
   width: 100%;
   padding: 0;
 }
 
 .theme-firebug .requests-list-headers-wrapper {
   padding: 0 !important;
 }