diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index 40151f12523..e1a32fb619b 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -5825,7 +5825,7 @@ INT WINAPI WSCDeinstallProvider(LPGUID lpProviderId, LPINT lpErrno)
  *              WSAAccept                        (WS2_32.26)
  */
 SOCKET WINAPI WSAAccept( SOCKET s, struct WS_sockaddr *addr, LPINT addrlen,
-               LPCONDITIONPROC lpfnCondition, DWORD dwCallbackData)
+               LPCONDITIONPROC lpfnCondition, DWORD_PTR dwCallbackData)
 {
 
        int ret = 0, size = 0;
@@ -5835,7 +5835,7 @@ SOCKET WINAPI WSAAccept( SOCKET s, struct WS_sockaddr *addr, LPINT addrlen,
        SOCKET cs;
        SOCKADDR src_addr, dst_addr;
 
-       TRACE("Socket %04lx, sockaddr %p, addrlen %p, fnCondition %p, dwCallbackData %d\n",
+       TRACE("Socket %04lx, sockaddr %p, addrlen %p, fnCondition %p, dwCallbackData %ld\n",
                s, addr, addrlen, lpfnCondition, dwCallbackData);
 
 
diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
index 87cd308dd19..7853a8ceabf 100644
--- a/dlls/ws2_32/tests/sock.c
+++ b/dlls/ws2_32/tests/sock.c
@@ -2467,7 +2467,7 @@ static void test_accept(void)
     ret = connect(connector, (struct sockaddr*)&address, sizeof(address));
     ok(ret == 0, "connecting to accepting socket failed, error %d\n", WSAGetLastError());
 
-    accepted = WSAAccept(server_socket, NULL, NULL, (LPCONDITIONPROC) AlwaysDeferConditionFunc, 0);
+    accepted = WSAAccept(server_socket, NULL, NULL, AlwaysDeferConditionFunc, 0);
     ok(accepted == INVALID_SOCKET && WSAGetLastError() == WSATRY_AGAIN, "Failed to defer connection, %d\n", WSAGetLastError());
 
     accepted = accept(server_socket, NULL, 0);
diff --git a/include/winsock2.h b/include/winsock2.h
index c3464738c4d..5e1f489b188 100644
--- a/include/winsock2.h
+++ b/include/winsock2.h
@@ -401,7 +401,7 @@ typedef int (CALLBACK *LPCONDITIONPROC)
     LPWSABUF lpCalleeId,
     LPWSABUF lpCalleeData,
     GROUP *g,
-    DWORD dwCallbackData
+    DWORD_PTR dwCallbackData
 );
 
 typedef void (CALLBACK *LPWSAOVERLAPPED_COMPLETION_ROUTINE)
@@ -604,7 +604,7 @@ typedef SOCKET (WINAPI *LPFN_SOCKET)(int,int,int);
  * "Winsock2 Function Typedefs" section below.
  */
 #if WS_API_PROTOTYPES
-SOCKET WINAPI WSAAccept(SOCKET,struct WS(sockaddr)*,LPINT,LPCONDITIONPROC,DWORD);
+SOCKET WINAPI WSAAccept(SOCKET,struct WS(sockaddr)*,LPINT,LPCONDITIONPROC,DWORD_PTR);
 INT WINAPI WSAAddressToStringA(LPSOCKADDR,DWORD,LPWSAPROTOCOL_INFOA,LPSTR,LPDWORD);
 INT WINAPI WSAAddressToStringW(LPSOCKADDR,DWORD,LPWSAPROTOCOL_INFOW,LPWSTR,LPDWORD);
 #define WSAAddressToString         WINELIB_NAME_AW(WSAAddressToString)
@@ -678,7 +678,7 @@ DWORD WINAPI WSAWaitForMultipleEvents(DWORD,const WSAEVENT*,BOOL,DWORD,BOOL);
  * "Winsock2 Prototypes" section above.
  */
 #if WS_API_TYPEDEFS
-typedef SOCKET (WINAPI *LPFN_WSAACCEPT)(SOCKET,WS(sockaddr)*,LPINT,LPCONDITIONPROC,DWORD);
+typedef SOCKET (WINAPI *LPFN_WSAACCEPT)(SOCKET,WS(sockaddr)*,LPINT,LPCONDITIONPROC,DWORD_PTR);
 typedef INT (WINAPI *LPFN_WSAADRESSTOSTRINGA)(LPSOCKADDR,DWORD,LPWSAPROTOCOL_INFOA,LPSTR,LPDWORD);
 typedef INT (WINAPI *LPFN_WSAADRESSTOSTRINGW)(LPSOCKADDR,DWORD,LPWSAPROTOCOL_INFOW,LPWSTR,LPDWORD);
 #define LPFN_WSAADDRESSTOSTRING    WINELIB_NAME_AW(LPFN_WSAADDRESSTOSTRING)