diff --git a/dom/media/webspeech/synth/speechd/SpeechDispatcherService.cpp b/dom/media/webspeech/synth/speechd/SpeechDispatcherService.cpp
index e30886c4d215..e1310f1fcba3 100644
--- a/dom/media/webspeech/synth/speechd/SpeechDispatcherService.cpp
+++ b/dom/media/webspeech/synth/speechd/SpeechDispatcherService.cpp
@@ -411,38 +411,24 @@ SpeechDispatcherService::Setup()
   //mInitialized = true;
 }
 
-struct VoiceTraverserData
-{
-  SpeechDispatcherService* mService;
-  nsSynthVoiceRegistry* mRegistry;
-};
-
 // private methods
 
-static PLDHashOperator
-AddVoiceTraverser(const nsAString& aUri,
-                  RefPtr<SpeechDispatcherVoice>& aVoice,
-                  void* aUserArg)
-{
-  VoiceTraverserData* data = static_cast<VoiceTraverserData*>(aUserArg);
-
-  // This service can only speak one utterance at a time, se we set
-  // aQueuesUtterances to true in order to track global state and schedule
-  // access to this service.
-  DebugOnly<nsresult> rv = data->mRegistry->AddVoice(data->mService, aUri,
-                                                     aVoice->mName, aVoice->mLanguage,
-                                                     aVoice->mName.EqualsLiteral("default"), true);
-
-  NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "Failed to add voice");
-
-  return PL_DHASH_NEXT;
-}
-
 void
 SpeechDispatcherService::RegisterVoices()
 {
-  VoiceTraverserData data = { this, nsSynthVoiceRegistry::GetInstance() };
-  mVoices.Enumerate(AddVoiceTraverser, &data);
+  nsSynthVoiceRegistry* registry = nsSynthVoiceRegistry::GetInstance();
+  for (auto iter = mVoices.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<SpeechDispatcherVoice>& voice = iter.Data();
+
+    // This service can only speak one utterance at a time, so we set
+    // aQueuesUtterances to true in order to track global state and schedule
+    // access to this service.
+    DebugOnly<nsresult> rv =
+      registry->AddVoice(this, iter.Key(), voice->mName, voice->mLanguage,
+                         voice->mName.EqualsLiteral("default"), true);
+
+    NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "Failed to add voice");
+  }
 
   mInitThread->Shutdown();
   mInitThread = nullptr;