--- a/netwerk/base/nsPACMan.cpp
+++ b/netwerk/base/nsPACMan.cpp
@@ -175,16 +175,17 @@ private:
 
 class ExecutePACThreadAction final : public Runnable
 {
 public:
   // by default we just process the queue
   explicit ExecutePACThreadAction(nsPACMan *aPACMan)
     : mPACMan(aPACMan)
     , mCancel(false)
+    , mCancelStatus(NS_OK)
     , mSetupPAC(false)
   { }
 
   void CancelQueue (nsresult status)
   {
     mCancel = true;
     mCancelStatus = status;
   }