--- a/devtools/install.rdf
+++ b/devtools/install.rdf
@@ -11,16 +11,17 @@
                em:id="devtools@mozilla.org"
                em:name="Developer Tools (local version)"
                em:description="Add-on to load DevTools from local sources and easily reload them with Ctrl+Alt+r shortcut"
                em:version="44.0a1"
                em:type="2"
                em:creator="Mozilla">
 
     <em:bootstrap>true</em:bootstrap>
+    <em:multiprocessCompatible>true</em:multiprocessCompatible>
     <em:targetApplication>
       <Description>
         <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
         <em:minVersion>44.0a1</em:minVersion>
         <em:maxVersion>*</em:maxVersion>
       </Description>
     </em:targetApplication>
   </Description>