--- a/devtools/client/themes/common.css
+++ b/devtools/client/themes/common.css
@@ -97,25 +97,23 @@ html|button, html|select {
 
 /* Rest of the dark and light theme */
 
 .devtools-autocomplete-popup,
 .CodeMirror-hints,
 .CodeMirror-Tern-tooltip {
   border: 1px solid hsl(210,24%,90%);
   background-image: linear-gradient(to bottom, hsla(209,18%,100%,0.9), hsl(210,24%,95%));
-  box-shadow: 0 1px 0 hsla(209,29%,90%,.25) inset;
 }
 
 .theme-dark .devtools-autocomplete-popup,
 .theme-dark .CodeMirror-hints,
 .theme-dark .CodeMirror-Tern-tooltip {
   border: 1px solid hsl(210,11%,10%);
   background-image: linear-gradient(to bottom, hsla(209,18%,18%,0.9), hsl(210,11%,16%));
-  box-shadow: none;
 }
 
 .theme-firebug .devtools-autocomplete-popup {
   border-color: var(--theme-splitter-color);
   border-radius: 5px;
   font-size: var(--theme-autompletion-font-size);
   background: var(--theme-body-background);
 }