--- a/rdf/base/nsRDFContentSink.cpp
+++ b/rdf/base/nsRDFContentSink.cpp
@@ -218,17 +218,17 @@ protected:
     struct RDFContextStackElement {
         nsCOMPtr<nsIRDFResource> mResource;
         RDFContentSinkState      mState;
         RDFContentSinkParseMode  mParseMode;
     };
 
     nsAutoTArray<RDFContextStackElement, 8>* mContextStack;
 
-    nsIURI*      mDocumentURL;
+    nsCOMPtr<nsIURI> mDocumentURL;
 
 private:
     static PRLogModuleInfo* gLog;
 };
 
 int32_t         RDFContentSinkImpl::gRefCnt = 0;
 nsIRDFService*  RDFContentSinkImpl::gRDFService;
 nsIRDFContainerUtils* RDFContentSinkImpl::gRDFContainerUtils;
@@ -258,18 +258,17 @@ static const nsStaticAtom rdf_atoms[] = 
 };
 
 RDFContentSinkImpl::RDFContentSinkImpl()
     : mText(nullptr),
       mTextLength(0),
       mTextSize(0),
       mState(eRDFContentSinkState_InProlog),
       mParseMode(eRDFContentSinkParseMode_Literal),
-      mContextStack(nullptr),
-      mDocumentURL(nullptr)
+      mContextStack(nullptr)
 {
     if (gRefCnt++ == 0) {
         NS_DEFINE_CID(kRDFServiceCID, NS_RDFSERVICE_CID);
         nsresult rv = CallGetService(kRDFServiceCID, &gRDFService);
 
         NS_ASSERTION(NS_SUCCEEDED(rv), "unable to get RDF service");
         if (NS_SUCCEEDED(rv)) {
             rv = gRDFService->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "type"),
@@ -299,18 +298,16 @@ RDFContentSinkImpl::RDFContentSinkImpl()
 
 RDFContentSinkImpl::~RDFContentSinkImpl()
 {
 #ifdef DEBUG_REFS
     --gInstanceCount;
     fprintf(stdout, "%d - RDF: RDFContentSinkImpl\n", gInstanceCount);
 #endif
 
-    NS_IF_RELEASE(mDocumentURL);
-
     if (mContextStack) {
         MOZ_LOG(gLog, LogLevel::Warning,
                ("rdfxml: warning! unclosed tag"));
 
         // XXX we should never need to do this, but, we'll write the
         // code all the same. If someone left the content stack dirty,
         // pop all the elements off the stack and release them.
         int32_t i = mContextStack->Length();
@@ -603,18 +600,16 @@ RDFContentSinkImpl::SetParser(nsParserBa
 NS_IMETHODIMP
 RDFContentSinkImpl::Init(nsIURI* aURL)
 {
     NS_PRECONDITION(aURL != nullptr, "null ptr");
     if (! aURL)
         return NS_ERROR_NULL_POINTER;
 
     mDocumentURL = aURL;
-    NS_ADDREF(aURL);
-
     mState = eRDFContentSinkState_InProlog;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 RDFContentSinkImpl::SetDataSource(nsIRDFDataSource* aDataSource)
 {
     NS_PRECONDITION(aDataSource != nullptr, "SetDataSource null ptr");