diff --git a/dom/plugins/BrowserStreamChild.cpp b/dom/plugins/BrowserStreamChild.cpp
index 4dbf38d42e6..9184cd6e135 100644
--- a/dom/plugins/BrowserStreamChild.cpp
+++ b/dom/plugins/BrowserStreamChild.cpp
@@ -61,19 +61,17 @@ BrowserStreamChild::BrowserStreamChild(PluginInstanceChild* instance,
 
   memset(&mStream, 0, sizeof(mStream));
   mStream.ndata = static_cast<AStream*>(this);
-  if (!mURL.IsEmpty())
-    mStream.url = mURL.get();
+  mStream.url = NullableStringGet(mURL);
   mStream.end = length;
   mStream.lastmodified = lastmodified;
   if (notifyData)
     mStream.notifyData =
       static_cast<const StreamNotifyChild*>(notifyData)->mClosure;
-  if (!mHeaders.IsEmpty())
-    mStream.headers = mHeaders.get();
+  mStream.headers = NullableStringGet(mHeaders);
 
-  *rv = mInstance->mPluginIface->newstream(&mInstance->mData,
-                                           const_cast<char*>(mimeType.get()),
-                                           &mStream, seekable, stype);
+  *rv = mInstance->mPluginIface->newstream(
+    &mInstance->mData, const_cast<char*>(NullableStringGet(mimeType)),
+    &mStream, seekable, stype);
   if (*rv != NPERR_NO_ERROR)
     mClosed = true;
 }
diff --git a/dom/plugins/PluginInstanceParent.cpp b/dom/plugins/PluginInstanceParent.cpp
index 5cd0d586b6b..ee76d69e39b 100644
--- a/dom/plugins/PluginInstanceParent.cpp
+++ b/dom/plugins/PluginInstanceParent.cpp
@@ -472,18 +472,18 @@ PluginInstanceParent::NPP_NewStream(NPMIMEType type, NPStream* stream,
                                     NPBool seekable, uint16_t* stype)
 {
     _MOZ_LOG(__FUNCTION__);
-        
+
     BrowserStreamParent* bs = new BrowserStreamParent(this, stream);
 
     NPError err;
-    // TODO are any of these strings nullable?
     if (!CallPBrowserStreamConstructor(bs,
-                                       nsCString(stream->url),
+                                       NullableString(stream->url),
                                        stream->end,
                                        stream->lastmodified,
                                        static_cast<PStreamNotifyParent*>(stream->notifyData),
-                                       nsCString(stream->headers),
-                                       nsCString(type), seekable, &err, stype))
+                                       NullableString(stream->headers),
+                                       NullableString(type), seekable,
+                                       &err, stype))
         return NPERR_GENERIC_ERROR;
 
     if (NPERR_NO_ERROR != err)