diff --git a/browser/devtools/styleinspector/csshtmltree.xul b/browser/devtools/styleinspector/csshtmltree.xul
index cad4f35ab636..79417ff8f9cd 100644
--- a/browser/devtools/styleinspector/csshtmltree.xul
+++ b/browser/devtools/styleinspector/csshtmltree.xul
@@ -90,14 +90,12 @@ To visually debug the templates without running firefox, alter the display:none
   styles" checkbox. For data it needs an instance of CssHtmlTree.
   -->
   <div id="templateRoot">
-    <xul:hbox class="headerControls" flex="1">
-      <label class="userStylesLabel">
-        <input class="onlyuserstyles" save="${onlyUserStylesCheckbox}"
-               type="checkbox" onchange="${onlyUserStylesChanged}" checked=""/>
-        &userStylesLabel;
-      </label>
+    <xul:hbox class="headerControls" flex="1" align="center">
+      <xul:checkbox class="onlyuserstyles" save="${onlyUserStylesCheckbox}"
+                    oncommand="${onlyUserStylesChanged}" checked="true"
+                    label="&userStylesLabel;"/>
       <xul:textbox class="searchfield" type="search" save="${searchField}"
-                   placeholder="&userStylesSearch;"
+                   placeholder="&userStylesSearch;" flex="1"
                    oncommand="${filterChanged}"/>
     </xul:hbox>
   </div>
diff --git a/browser/themes/gnomestripe/browser/devtools/csshtmltree.css b/browser/themes/gnomestripe/browser/devtools/csshtmltree.css
index 1d643f02f04e..f6977d95eeb0 100644
--- a/browser/themes/gnomestripe/browser/devtools/csshtmltree.css
+++ b/browser/themes/gnomestripe/browser/devtools/csshtmltree.css
@@ -224,27 +224,13 @@
   padding-top: 5px;
 }
 
-.onlyuserstyles,
-.userStylesLabel {
-  cursor: pointer;
-}
-
-.userStylesLabel {
-  display: -moz-box;
-  white-space: nowrap;
-}
-
 .onlyuserstyles {
-  position: relative;
-  top: 3px;
-  font-family: sans-serif;
+  cursor: pointer;
   font-size: 11px;
 }
 
 .searchfield {
-  display: -moz-box;
-  -moz-box-flex: 1;
-  margin-left: 10px;
+  -moz-margin-start: 10px;
 }
 
 .styleinspector-legend {
diff --git a/browser/themes/pinstripe/browser/devtools/csshtmltree.css b/browser/themes/pinstripe/browser/devtools/csshtmltree.css
index e62f2a96b473..86a584a85bce 100644
--- a/browser/themes/pinstripe/browser/devtools/csshtmltree.css
+++ b/browser/themes/pinstripe/browser/devtools/csshtmltree.css
@@ -226,27 +226,13 @@
   padding-top: 5px;
 }
 
-.onlyuserstyles,
-.userStylesLabel {
-  cursor: pointer;
-}
-
-.userStylesLabel {
-  display: -moz-box;
-  white-space: nowrap;
-}
-
 .onlyuserstyles {
-  position: relative;
-  top: 3px;
-  font-family: sans-serif;
+  cursor: pointer;
   font-size: 11px;
 }
 
 .searchfield {
-  display: -moz-box;
-  -moz-box-flex: 1;
-  margin-left: 10px;
+  -moz-margin-start: 10px;
 }
 
 .styleinspector-legend {
diff --git a/browser/themes/winstripe/browser/devtools/csshtmltree.css b/browser/themes/winstripe/browser/devtools/csshtmltree.css
index c5f5d3798d89..be962a00ed9d 100644
--- a/browser/themes/winstripe/browser/devtools/csshtmltree.css
+++ b/browser/themes/winstripe/browser/devtools/csshtmltree.css
@@ -226,27 +226,13 @@
   padding-top: 5px;
 }
 
-.onlyuserstyles,
-.userStylesLabel {
-  cursor: pointer;
-}
-
-.userStylesLabel {
-  display: -moz-box;
-  white-space: nowrap;
-}
-
 .onlyuserstyles {
-  position: relative;
-  top: 3px;
-  font-family: sans-serif;
+  cursor: pointer;
   font-size: 11px;
 }
 
 .searchfield {
-  display: -moz-box;
-  -moz-box-flex: 1;
-  margin-left: 10px;
+  -moz-margin-start: 10px;
 }
 
 .styleinspector-legend {