diff --git a/dlls/ntdll/unix/socket.c b/dlls/ntdll/unix/socket.c
index b988253c67a..6b4b4a9b3f8 100644
--- a/dlls/ntdll/unix/socket.c
+++ b/dlls/ntdll/unix/socket.c
@@ -91,6 +91,8 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(winsock);
 
+#define u64_to_user_ptr(u) ((void *)(uintptr_t)(u))
+
 union unix_sockaddr
 {
     struct sockaddr addr;
@@ -1414,6 +1416,7 @@ NTSTATUS sock_ioctl( HANDLE handle, HANDLE event, PIO_APC_ROUTINE apc, void *apc
         case IOCTL_AFD_WINE_RECVMSG:
         {
             struct afd_recvmsg_params *params = in_buffer;
+            unsigned int *ws_flags = u64_to_user_ptr(params->ws_flags_ptr);
             int unix_flags = 0;
 
             if ((status = server_get_unix_fd( handle, 0, &fd, &needs_close, NULL, NULL )))
@@ -1425,15 +1428,17 @@ NTSTATUS sock_ioctl( HANDLE handle, HANDLE event, PIO_APC_ROUTINE apc, void *apc
                 break;
             }
 
-            if (*params->ws_flags & WS_MSG_OOB)
+            if (*ws_flags & WS_MSG_OOB)
                 unix_flags |= MSG_OOB;
-            if (*params->ws_flags & WS_MSG_PEEK)
+            if (*ws_flags & WS_MSG_PEEK)
                 unix_flags |= MSG_PEEK;
-            if (*params->ws_flags & WS_MSG_WAITALL)
+            if (*ws_flags & WS_MSG_WAITALL)
                 FIXME( "MSG_WAITALL is not supported\n" );
 
-            status = sock_recv( handle, event, apc, apc_user, io, fd, params->buffers, params->count, params->control,
-                                params->addr, params->addr_len, params->ws_flags, unix_flags, params->force_async );
+            status = sock_recv( handle, event, apc, apc_user, io, fd, u64_to_user_ptr(params->buffers_ptr),
+                                params->count, u64_to_user_ptr(params->control_ptr),
+                                u64_to_user_ptr(params->addr_ptr), u64_to_user_ptr(params->addr_len_ptr),
+                                ws_flags, unix_flags, params->force_async );
             break;
         }
 
diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index 2db441bee3c..33df823b213 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -35,6 +35,8 @@ WINE_DECLARE_DEBUG_CHANNEL(winediag);
 
 #define TIMEOUT_INFINITE _I64_MAX
 
+#define u64_from_user_ptr(ptr) ((ULONGLONG)(uintptr_t)(ptr))
+
 static const WSAPROTOCOL_INFOW supported_protocols[] =
 {
     {
@@ -923,13 +925,13 @@ static int WS2_recv_base( SOCKET s, WSABUF *buffers, DWORD buffer_count, DWORD *
         apc = socket_apc;
     }
 
-    params.control = control;
-    params.addr = addr;
-    params.addr_len = addr_len;
-    params.ws_flags = flags;
+    params.control_ptr = u64_from_user_ptr(control);
+    params.addr_ptr = u64_from_user_ptr(addr);
+    params.addr_len_ptr = u64_from_user_ptr(addr_len);
+    params.ws_flags_ptr = u64_from_user_ptr(flags);
     params.force_async = !!overlapped;
     params.count = buffer_count;
-    params.buffers = buffers;
+    params.buffers_ptr = u64_from_user_ptr(buffers);
 
     status = NtDeviceIoControlFile( (HANDLE)s, event, apc, cvalue, piosb,
                                     IOCTL_AFD_WINE_RECVMSG, &params, sizeof(params), NULL, 0 );
diff --git a/include/wine/afd.h b/include/wine/afd.h
index 9d1af44f117..7db429c2b79 100644
--- a/include/wine/afd.h
+++ b/include/wine/afd.h
@@ -281,14 +281,15 @@ C_ASSERT( sizeof(struct afd_connect_params) == 8 );
 
 struct afd_recvmsg_params
 {
-    WSABUF *control;
-    struct WS(sockaddr) *addr;
-    int *addr_len;
-    unsigned int *ws_flags;
+    ULONGLONG control_ptr; /* WSABUF */
+    ULONGLONG addr_ptr; /* WS(sockaddr) */
+    ULONGLONG addr_len_ptr; /* int */
+    ULONGLONG ws_flags_ptr; /* unsigned int */
     int force_async;
     unsigned int count;
-    WSABUF *buffers;
+    ULONGLONG buffers_ptr; /* WSABUF[] */
 };
+C_ASSERT( sizeof(struct afd_recvmsg_params) == 48 );
 
 struct afd_sendmsg_params
 {