--- a/dom/media/webspeech/recognition/PocketSphinxSpeechRecognitionService.cpp
+++ b/dom/media/webspeech/recognition/PocketSphinxSpeechRecognitionService.cpp
@@ -9,16 +9,17 @@
 #include "PocketSphinxSpeechRecognitionService.h"
 #include "nsIFile.h"
 #include "SpeechGrammar.h"
 #include "SpeechRecognition.h"
 #include "SpeechRecognitionAlternative.h"
 #include "SpeechRecognitionResult.h"
 #include "SpeechRecognitionResultList.h"
 #include "nsIObserverService.h"
+#include "MediaPrefs.h"
 #include "mozilla/Services.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsDirectoryServiceUtils.h"
 #include "nsMemory.h"
 
 extern "C" {
 #include "pocketsphinx/pocketsphinx.h"
 #include "sphinxbase/logmath.h"
@@ -297,17 +298,17 @@ PocketSphinxSpeechRecognitionService::Ab
   return NS_OK;
 }
 
 NS_IMETHODIMP
 PocketSphinxSpeechRecognitionService::Observe(nsISupports* aSubject,
                                               const char* aTopic,
                                               const char16_t* aData)
 {
-  MOZ_ASSERT(mRecognition->mTestConfig.mFakeRecognitionService,
+  MOZ_ASSERT(MediaPrefs::WebSpeechFakeRecognitionService(),
              "Got request to fake recognition service event, "
              "but " TEST_PREFERENCE_FAKE_RECOGNITION_SERVICE " is not set");
 
   if (!strcmp(aTopic, SPEECH_RECOGNITION_TEST_END_TOPIC)) {
     nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
     obs->RemoveObserver(this, SPEECH_RECOGNITION_TEST_EVENT_REQUEST_TOPIC);
     obs->RemoveObserver(this, SPEECH_RECOGNITION_TEST_END_TOPIC);