diff --git a/src/plugins/simulator/fs9/directplaypeer.cpp b/src/plugins/simulator/fs9/directplaypeer.cpp
index 4eb6ef94f..7495f6f7b 100644
--- a/src/plugins/simulator/fs9/directplaypeer.cpp
+++ b/src/plugins/simulator/fs9/directplaypeer.cpp
@@ -48,8 +48,6 @@ namespace BlackSimPlugin
 
         HRESULT CDirectPlayPeer::directPlayMessageHandler(DWORD messageId, void *msgBuffer)
         {
-            HRESULT hr = S_OK;
-
             switch (messageId)
             {
             case DPN_MSGID_CREATE_PLAYER:
@@ -162,7 +160,9 @@ namespace BlackSimPlugin
 
             }
 
-            return hr;
+            // Directx9 SDK: Unless otherwise noted, this function should return S_OK.
+            // http://doc.51windows.net/Directx9_SDK/play/ref/callbacks/pfndpnmessagehandler.htm
+            return S_OK;
         }
 
         HRESULT CDirectPlayPeer::initDirectPlay()
diff --git a/src/plugins/simulator/fs9/directplaypeer.h b/src/plugins/simulator/fs9/directplaypeer.h
index 7c2e56809..1197fcc4b 100644
--- a/src/plugins/simulator/fs9/directplaypeer.h
+++ b/src/plugins/simulator/fs9/directplaypeer.h
@@ -28,6 +28,8 @@ namespace BlackSimPlugin
     namespace Fs9
     {
         //! DirectPlay peer implementation
+        //! More information can be found in the DirectX9 SDK documentation
+        //! http://doc.51windows.net/Directx9_SDK/?url=/Directx9_SDK/play/dplay.htm
         class CDirectPlayPeer : public BlackMisc::CContinuousWorker
         {
             Q_OBJECT