diff --git a/dlls/dplayx/dplay.c b/dlls/dplayx/dplay.c
index 650adfd9bff..17ebd00a281 100644
--- a/dlls/dplayx/dplay.c
+++ b/dlls/dplayx/dplay.c
@@ -54,12 +54,12 @@ static lpPlayerList DP_FindPlayer( IDirectPlay2AImpl* This, DPID dpid );
 static lpPlayerData DP_CreatePlayer( IDirectPlay2Impl* iface, LPDPID lpid,
                                      LPDPNAME lpName, DWORD dwFlags,
                                      HANDLE hEvent, BOOL bAnsi );
-static BOOL DP_CopyDPNAMEStruct( LPDPNAME lpDst, LPDPNAME lpSrc, BOOL bAnsi );
+static BOOL DP_CopyDPNAMEStruct( LPDPNAME lpDst, const DPNAME *lpSrc, BOOL bAnsi );
 static void DP_SetPlayerData( lpPlayerData lpPData, DWORD dwFlags,
                               LPVOID lpData, DWORD dwDataSize );
 
-static lpGroupData DP_CreateGroup( IDirectPlay2AImpl* iface, LPDPID lpid,
-                                   LPDPNAME lpName, DWORD dwFlags,
+static lpGroupData DP_CreateGroup( IDirectPlay2AImpl* iface, const DPID *lpid,
+                                   const DPNAME *lpName, DWORD dwFlags,
                                    DPID idParent, BOOL bAnsi );
 static void DP_SetGroupData( lpGroupData lpGData, DWORD dwFlags,
                              LPVOID lpData, DWORD dwDataSize );
@@ -919,8 +919,8 @@ static HRESULT WINAPI DirectPlay2WImpl_Close
 }
 
 static
-lpGroupData DP_CreateGroup( IDirectPlay2AImpl* This, LPDPID lpid,
-                            LPDPNAME lpName, DWORD dwFlags,
+lpGroupData DP_CreateGroup( IDirectPlay2AImpl* This, const DPID *lpid,
+                            const DPNAME *lpName, DWORD dwFlags,
                             DPID idParent, BOOL bAnsi )
 {
   lpGroupData lpGData;
@@ -1290,7 +1290,7 @@ static lpPlayerList DP_FindPlayer( IDirectPlay2AImpl* This, DPID dpid )
 }
 
 /* Basic area for Dst must already be allocated */
-static BOOL DP_CopyDPNAMEStruct( LPDPNAME lpDst, LPDPNAME lpSrc, BOOL bAnsi )
+static BOOL DP_CopyDPNAMEStruct( LPDPNAME lpDst, const DPNAME *lpSrc, BOOL bAnsi )
 {
   if( lpSrc == NULL )
   {
diff --git a/dlls/dplayx/dplayx_global.c b/dlls/dplayx/dplayx_global.c
index 13bf1e21812..9ad9b3e366a 100644
--- a/dlls/dplayx/dplayx_global.c
+++ b/dlls/dplayx/dplayx_global.c
@@ -199,10 +199,10 @@ static DPSESSIONDESC2* sessionData = NULL;
 /* static DPSESSIONDESC2* sessionData[ numSupportedSessions ]; */
 
 /* Function prototypes */
-static DWORD DPLAYX_SizeOfLobbyDataA( LPDPLCONNECTION lpDplData );
-static DWORD DPLAYX_SizeOfLobbyDataW( LPDPLCONNECTION lpDplData );
-static void DPLAYX_CopyConnStructA( LPDPLCONNECTION dest, LPDPLCONNECTION src );
-static void DPLAYX_CopyConnStructW( LPDPLCONNECTION dest, LPDPLCONNECTION src );
+static DWORD DPLAYX_SizeOfLobbyDataA( const DPLCONNECTION *lpDplData );
+static DWORD DPLAYX_SizeOfLobbyDataW( const DPLCONNECTION *lpDplData );
+static void DPLAYX_CopyConnStructA( LPDPLCONNECTION dest, const DPLCONNECTION *src );
+static void DPLAYX_CopyConnStructW( LPDPLCONNECTION dest, const DPLCONNECTION *src );
 static BOOL DPLAYX_IsAppIdLobbied( DWORD dwAppId, LPDPLAYX_LOBBYDATA* dplData );
 static void DPLAYX_InitializeLobbyDataEntry( LPDPLAYX_LOBBYDATA lpData );
 static BOOL DPLAYX_CopyIntoSessionDesc2A( LPDPSESSIONDESC2  lpSessionDest,
@@ -658,7 +658,7 @@ HRESULT DPLAYX_GetConnectionSettingsA
 }
 
 /* Assumption: Enough contiguous space was allocated at dest */
-void DPLAYX_CopyConnStructA( LPDPLCONNECTION dest, LPDPLCONNECTION src )
+void DPLAYX_CopyConnStructA( LPDPLCONNECTION dest, const DPLCONNECTION *src )
 {
   BYTE* lpStartOfFreeSpace;
 
@@ -780,7 +780,7 @@ HRESULT DPLAYX_GetConnectionSettingsW
 }
 
 /* Assumption: Enough contiguous space was allocated at dest */
-void DPLAYX_CopyConnStructW( LPDPLCONNECTION dest, LPDPLCONNECTION src )
+void DPLAYX_CopyConnStructW( LPDPLCONNECTION dest, const DPLCONNECTION *src )
 {
   BYTE*              lpStartOfFreeSpace;
 
@@ -855,7 +855,7 @@ void DPLAYX_CopyConnStructW( LPDPLCONNECTION dest, LPDPLCONNECTION src )
 HRESULT DPLAYX_SetConnectionSettingsA
 ( DWORD dwFlags,
   DWORD dwAppID,
-  LPDPLCONNECTION lpConn )
+  const DPLCONNECTION *lpConn )
 {
   LPDPLAYX_LOBBYDATA lpDplData;
 
@@ -917,7 +917,7 @@ HRESULT DPLAYX_SetConnectionSettingsA
 HRESULT DPLAYX_SetConnectionSettingsW
 ( DWORD dwFlags,
   DWORD dwAppID,
-  LPDPLCONNECTION lpConn )
+  const DPLCONNECTION *lpConn )
 {
   LPDPLAYX_LOBBYDATA lpDplData;
 
@@ -961,7 +961,7 @@ HRESULT DPLAYX_SetConnectionSettingsW
   return DP_OK;
 }
 
-DWORD DPLAYX_SizeOfLobbyDataA( LPDPLCONNECTION lpConn )
+DWORD DPLAYX_SizeOfLobbyDataA( const DPLCONNECTION *lpConn )
 {
   DWORD dwTotalSize = sizeof( DPLCONNECTION );
 
@@ -1008,7 +1008,7 @@ DWORD DPLAYX_SizeOfLobbyDataA( LPDPLCONNECTION lpConn )
   return dwTotalSize;
 }
 
-DWORD DPLAYX_SizeOfLobbyDataW( LPDPLCONNECTION lpConn )
+DWORD DPLAYX_SizeOfLobbyDataW( const DPLCONNECTION *lpConn )
 {
   DWORD dwTotalSize = sizeof( DPLCONNECTION );
 
diff --git a/dlls/dplayx/dplayx_global.h b/dlls/dplayx/dplayx_global.h
index d7f7e73ce93..a4d109a9c9b 100644
--- a/dlls/dplayx/dplayx_global.h
+++ b/dlls/dplayx/dplayx_global.h
@@ -38,10 +38,10 @@ HRESULT DPLAYX_GetConnectionSettingsW ( DWORD dwAppID,
 
 HRESULT DPLAYX_SetConnectionSettingsA ( DWORD dwFlags,
                                         DWORD dwAppID,
-                                        LPDPLCONNECTION lpConn );
+                                        const DPLCONNECTION *lpConn );
 HRESULT DPLAYX_SetConnectionSettingsW ( DWORD dwFlags,
                                         DWORD dwAppID,
-                                        LPDPLCONNECTION lpConn );
+                                        const DPLCONNECTION *lpConn );
 
 BOOL DPLAYX_CreateLobbyApplication( DWORD dwAppID );
 BOOL DPLAYX_DestroyLobbyApplication( DWORD dwAppID );
diff --git a/dlls/dplayx/name_server.c b/dlls/dplayx/name_server.c
index f46af67c956..e875c19063a 100644
--- a/dlls/dplayx/name_server.c
+++ b/dlls/dplayx/name_server.c
@@ -211,7 +211,7 @@ void NS_SetLocalAddr( LPVOID lpNSInfo, LPCVOID lpHdr, DWORD dwHdrSize )
  */
 HRESULT NS_SendSessionRequestBroadcast( LPCGUID lpcGuid,
                                         DWORD dwFlags,
-                                        LPSPINITDATA lpSpData )
+                                        const SPINITDATA *lpSpData )
 
 {
   DPSP_ENUMSESSIONSDATA data;
diff --git a/dlls/dplayx/name_server.h b/dlls/dplayx/name_server.h
index ec2c298191a..2df4a3bf7ea 100644
--- a/dlls/dplayx/name_server.h
+++ b/dlls/dplayx/name_server.h
@@ -46,7 +46,7 @@ void NS_ReplyToEnumSessionsRequest( LPCVOID lpcMsg,
 
 HRESULT NS_SendSessionRequestBroadcast( LPCGUID lpcGuid,
                                         DWORD dwFlags,
-                                        LPSPINITDATA lpSpData );
+                                        const SPINITDATA *lpSpData );
 
 
 BOOL NS_InitializeSessionCache( LPVOID* lplpNSInfo );