diff --git a/dlls/ntdll/file.c b/dlls/ntdll/file.c
index 0a070b5e885..1dfbd0140c3 100644
--- a/dlls/ntdll/file.c
+++ b/dlls/ntdll/file.c
@@ -1198,6 +1198,7 @@ static NTSTATUS server_ioctl_file( HANDLE handle, HANDLE event,
     SERVER_START_REQ( ioctl )
     {
         req->code           = code;
+        req->blocking       = !apc && !event;
         req->async.handle   = wine_server_obj_handle( handle );
         req->async.callback = ioctl_completion;
         req->async.iosb     = io;
diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index 521f7275413..91656dfd4d4 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -2710,6 +2710,7 @@ struct ioctl_request
     struct request_header __header;
     ioctl_code_t   code;
     async_data_t   async;
+    int            blocking;
     /* VARARG(in_data,bytes); */
 };
 struct ioctl_reply
@@ -5059,6 +5060,6 @@ union generic_reply
     struct set_window_layered_info_reply set_window_layered_info_reply;
 };
 
-#define SERVER_PROTOCOL_VERSION 370
+#define SERVER_PROTOCOL_VERSION 371
 
 #endif /* __WINE_WINE_SERVER_PROTOCOL_H */
diff --git a/server/device.c b/server/device.c
index 48bccd26fb0..9de2f548c34 100644
--- a/server/device.c
+++ b/server/device.c
@@ -125,7 +125,7 @@ static struct object *device_open_file( struct object *obj, unsigned int access,
                                         unsigned int sharing, unsigned int options );
 static enum server_fd_type device_get_fd_type( struct fd *fd );
 static obj_handle_t device_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async_data,
-                                  const void *data, data_size_t size );
+                                  int blocking, const void *data, data_size_t size );
 
 static const struct object_ops device_ops =
 {
@@ -308,7 +308,7 @@ static struct ioctl_call *find_ioctl_call( struct device *device, struct thread
 }
 
 static obj_handle_t device_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async_data,
-                                  const void *data, data_size_t size )
+                                  int blocking, const void *data, data_size_t size )
 {
     struct device *device = get_fd_user( fd );
     struct ioctl_call *ioctl;
diff --git a/server/fd.c b/server/fd.c
index 09b93ce06e1..c8b6f7aa702 100644
--- a/server/fd.c
+++ b/server/fd.c
@@ -1912,7 +1912,7 @@ static void unmount_device( struct fd *device_fd )
 
 /* default ioctl() routine */
 obj_handle_t default_fd_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async,
-                               const void *data, data_size_t size )
+                               int blocking, const void *data, data_size_t size )
 {
     switch(code)
     {
@@ -2015,7 +2015,7 @@ DECL_HANDLER(ioctl)
 
     if (fd)
     {
-        reply->wait = fd->fd_ops->ioctl( fd, req->code, &req->async,
+        reply->wait = fd->fd_ops->ioctl( fd, req->code, &req->async, req->blocking,
                                          get_req_data(), get_req_data_size() );
         reply->options = fd->options;
         release_object( fd );
diff --git a/server/file.h b/server/file.h
index b9a83c3f83d..3abfc0289f4 100644
--- a/server/file.h
+++ b/server/file.h
@@ -39,7 +39,7 @@ struct fd_ops
     /* get file information */
     enum server_fd_type (*get_fd_type)(struct fd *fd);
     /* perform an ioctl on the file */
-    obj_handle_t (*ioctl)(struct fd *fd, ioctl_code_t code, const async_data_t *async,
+    obj_handle_t (*ioctl)(struct fd *fd, ioctl_code_t code, const async_data_t *async, int blocking,
                           const void *data, data_size_t size);
     /* queue an async operation */
     void (*queue_async)(struct fd *, const async_data_t *data, int type, int count);
@@ -79,7 +79,7 @@ extern struct async *fd_queue_async( struct fd *fd, const async_data_t *data, in
 extern void fd_async_wake_up( struct fd *fd, int type, unsigned int status );
 extern void fd_reselect_async( struct fd *fd, struct async_queue *queue );
 extern obj_handle_t default_fd_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async,
-                                      const void *data, data_size_t size );
+                                      int blocking, const void *data, data_size_t size );
 extern void default_fd_queue_async( struct fd *fd, const async_data_t *data, int type, int count );
 extern void default_fd_reselect_async( struct fd *fd, struct async_queue *queue );
 extern void default_fd_cancel_async( struct fd *fd );
diff --git a/server/named_pipe.c b/server/named_pipe.c
index e9cb14a31d7..1651a67ff46 100644
--- a/server/named_pipe.c
+++ b/server/named_pipe.c
@@ -140,7 +140,7 @@ static void pipe_server_destroy( struct object *obj);
 static void pipe_server_flush( struct fd *fd, struct event **event );
 static enum server_fd_type pipe_server_get_fd_type( struct fd *fd );
 static obj_handle_t pipe_server_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async,
-                                       const void *data, data_size_t size );
+                                       int blocking, const void *data, data_size_t size );
 
 static const struct object_ops pipe_server_ops =
 {
@@ -223,7 +223,7 @@ static struct object *named_pipe_device_open_file( struct object *obj, unsigned
 static void named_pipe_device_destroy( struct object *obj );
 static enum server_fd_type named_pipe_device_get_fd_type( struct fd *fd );
 static obj_handle_t named_pipe_device_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async_data,
-                                             const void *data, data_size_t size );
+                                             int blocking, const void *data, data_size_t size );
 
 static const struct object_ops named_pipe_device_ops =
 {
@@ -592,7 +592,7 @@ static obj_handle_t alloc_wait_event( struct process *process )
 }
 
 static obj_handle_t pipe_server_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async_data,
-                                       const void *data, data_size_t size )
+                                       int blocking, const void *data, data_size_t size )
 {
     struct pipe_server *server = get_fd_user( fd );
     struct async *async;
@@ -605,7 +605,7 @@ static obj_handle_t pipe_server_ioctl( struct fd *fd, ioctl_code_t code, const a
         {
         case ps_idle_server:
         case ps_wait_connect:
-            if (!async_data->event && !async_data->apc)
+            if (blocking)
             {
                 async_data_t new_data = *async_data;
                 if (!(wait_handle = alloc_wait_event( current->process ))) break;
@@ -673,7 +673,7 @@ static obj_handle_t pipe_server_ioctl( struct fd *fd, ioctl_code_t code, const a
         return 0;
 
     default:
-        return default_fd_ioctl( fd, code, async_data, data, size );
+        return default_fd_ioctl( fd, code, async_data, blocking, data, size );
     }
 }
 
@@ -854,7 +854,7 @@ static struct object *named_pipe_open_file( struct object *obj, unsigned int acc
 }
 
 static obj_handle_t named_pipe_device_ioctl( struct fd *fd, ioctl_code_t code, const async_data_t *async_data,
-                                             const void *data, data_size_t size )
+                                             int blocking, const void *data, data_size_t size )
 {
     struct named_pipe_device *device = get_fd_user( fd );
 
@@ -887,7 +887,7 @@ static obj_handle_t named_pipe_device_ioctl( struct fd *fd, ioctl_code_t code, c
 
                 if (!pipe->waiters && !(pipe->waiters = create_async_queue( NULL ))) goto done;
 
-                if (!async_data->event && !async_data->apc)
+                if (blocking)
                 {
                     async_data_t new_data = *async_data;
                     if (!(wait_handle = alloc_wait_event( current->process ))) goto done;
@@ -916,7 +916,7 @@ static obj_handle_t named_pipe_device_ioctl( struct fd *fd, ioctl_code_t code, c
         }
 
     default:
-        return default_fd_ioctl( fd, code, async_data, data, size );
+        return default_fd_ioctl( fd, code, async_data, blocking, data, size );
     }
 }
 
diff --git a/server/protocol.def b/server/protocol.def
index 62717a5fa32..397c54e1d7f 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -2003,6 +2003,7 @@ enum message_type
 @REQ(ioctl)
     ioctl_code_t   code;          /* ioctl code */
     async_data_t   async;         /* async I/O parameters */
+    int            blocking;      /* whether it's a blocking ioctl */
     VARARG(in_data,bytes);        /* ioctl input data */
 @REPLY
     obj_handle_t   wait;          /* handle to wait on for blocking ioctl */
diff --git a/server/trace.c b/server/trace.c
index d2a7cec7507..60b23183c3d 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -2591,6 +2591,7 @@ static void dump_ioctl_request( const struct ioctl_request *req )
     fprintf( stderr, " async=" );
     dump_async_data( &req->async );
     fprintf( stderr, "," );
+    fprintf( stderr, " blocking=%d,", req->blocking );
     fprintf( stderr, " in_data=" );
     dump_varargs_bytes( cur_size );
 }