--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -2178,16 +2178,24 @@ ShowProfileManager(nsIToolkitProfileServ
   SaveFileToEnv("XRE_PROFILE_LOCAL_PATH", profLD);
   SaveWordToEnv("XRE_PROFILE_NAME", profileName);
 
   bool offline = false;
   aProfileSvc->GetStartOffline(&offline);
   if (offline) {
     SaveToEnv("XRE_START_OFFLINE=1");
   }
+  if (gRestartedByOS) {
+    // Re-add this argument when actually starting the application.
+    char** newArgv = (char**) realloc(gRestartArgv, sizeof(char*) * (gRestartArgc + 2));
+    NS_ENSURE_TRUE(newArgv, NS_ERROR_OUT_OF_MEMORY);
+    gRestartArgv = newArgv;
+    gRestartArgv[gRestartArgc++] = const_cast<char*>("-os-restarted");
+    gRestartArgv[gRestartArgc] = nullptr;
+  }
 
   return LaunchChild(aNative);
 }
 
 /**
  * Get the currently running profile using its root directory.
  *
  * @param aProfileSvc         The profile service