--- a/dom/fetch/FetchDriver.cpp
+++ b/dom/fetch/FetchDriver.cpp
@@ -1476,17 +1476,17 @@ FetchDriver::SetRequestHeaders(nsIHttpCh
                                  false /* merge */);
     MOZ_ASSERT(NS_SUCCEEDED(rv));
   }
 
   if (mRequest->ForceOriginHeader()) {
     nsAutoString origin;
     if (NS_SUCCEEDED(nsContentUtils::GetUTFOrigin(mPrincipal, origin))) {
       DebugOnly<nsresult> rv =
-        aChannel->SetRequestHeader(NS_LITERAL_CSTRING("origin"),
+        aChannel->SetRequestHeader(nsDependentCString(net::nsHttp::Origin),
                                    NS_ConvertUTF16toUTF8(origin),
                                    false /* merge */);
       MOZ_ASSERT(NS_SUCCEEDED(rv));
     }
   }
 }
 
 void

--- a/netwerk/protocol/http/nsCORSListenerProxy.cpp
+++ b/netwerk/protocol/http/nsCORSListenerProxy.cpp
@@ -1008,17 +1008,17 @@ nsCORSListenerProxy::UpdateChannel(nsICh
   // Add the Origin header
   nsAutoCString origin;
   rv = nsContentUtils::GetASCIIOrigin(mOriginHeaderPrincipal, origin);
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(aChannel);
   NS_ENSURE_TRUE(http, NS_ERROR_FAILURE);
 
-  rv = http->SetRequestHeader(NS_LITERAL_CSTRING("Origin"), origin, false);
+  rv = http->SetRequestHeader(nsDependentCString(net::nsHttp::Origin), origin, false);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Make cookie-less if needed. We don't need to do anything here if the
   // channel was opened with AsyncOpen2, since then AsyncOpen2 will take
   // care of the cookie policy for us.
   if (!mWithCredentials &&
       (!loadInfo || !loadInfo->GetEnforceSecurity())) {
     nsLoadFlags flags;