--- a/tools/profiler/gecko/nsIProfiler.idl
+++ b/tools/profiler/gecko/nsIProfiler.idl
@@ -13,17 +13,17 @@
 [ref] native nsCString(const nsCString);
 [ref] native StringArrayRef(const nsTArray<nsCString>);
 
 /**
  * Start-up parameters for subprocesses are passed through nsIObserverService,
  * which, unfortunately, means we need to implement nsISupports in order to
  * go through it.
  */
-[builtinclass, uuid(0a175ba7-8fcf-4ce9-9c4b-ccc6272f4425)]
+[scriptable, builtinclass, uuid(0a175ba7-8fcf-4ce9-9c4b-ccc6272f4425)]
 interface nsIProfilerStartParams : nsISupports
 {
   readonly attribute uint32_t entries;
   readonly attribute double interval;
   readonly attribute uint32_t features;
 
   [noscript, notxpcom, nostdcall] StringArrayRef getFilters();
 };