--- a/devtools/client/shared/test/browser_html_tooltip-02.js
+++ b/devtools/client/shared/test/browser_html_tooltip-02.js
@@ -6,16 +6,17 @@
 
 /**
  * Test the HTMLTooltip is closed when clicking outside of its container.
  */
 
 const HTML_NS = "http://www.w3.org/1999/xhtml";
 const TEST_URI = `data:text/xml;charset=UTF-8,<?xml version="1.0"?>
   <?xml-stylesheet href="chrome://global/skin/global.css"?>
+  <?xml-stylesheet href="chrome://devtools/skin/common.css"?>
   <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
    title="Tooltip test">
     <vbox flex="1">
       <hbox id="box1" flex="1">test1</hbox>
       <hbox id="box2" flex="1">test2</hbox>
       <hbox id="box3" flex="1">test3</hbox>
       <hbox id="box4" flex="1">test4</hbox>
     </vbox>

--- a/devtools/client/shared/test/browser_html_tooltip-03.js
+++ b/devtools/client/shared/test/browser_html_tooltip-03.js
@@ -6,16 +6,17 @@
 
 /**
  * Test the HTMLTooltip autofocus configuration option.
  */
 
 const HTML_NS = "http://www.w3.org/1999/xhtml";
 const TEST_URI = `data:text/xml;charset=UTF-8,<?xml version="1.0"?>
   <?xml-stylesheet href="chrome://global/skin/global.css"?>
+  <?xml-stylesheet href="chrome://devtools/skin/common.css"?>
   <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
    title="Tooltip test">
     <vbox flex="1">
       <hbox id="box1" flex="1">test1</hbox>
       <hbox id="box2" flex="1">test2</hbox>
       <hbox id="box3" flex="1">test3</hbox>
       <hbox id="box4" flex="1">
         <textbox id="box4-input"></textbox>