diff --git a/server/fd.c b/server/fd.c
index 1459ad1277d..eba3256e76e 100644
--- a/server/fd.c
+++ b/server/fd.c
@@ -1930,6 +1930,12 @@ unsigned int get_fd_options( struct fd *fd )
     return fd->options;
 }
 
+/* check if fd is in overlapped mode */
+int is_fd_overlapped( struct fd *fd )
+{
+    return !(fd->options & (FILE_SYNCHRONOUS_IO_ALERT | FILE_SYNCHRONOUS_IO_NONALERT));
+}
+
 /* retrieve the unix fd for an object */
 int get_unix_fd( struct fd *fd )
 {
@@ -2611,7 +2617,7 @@ DECL_HANDLER(set_completion_info)
 
     if (fd)
     {
-        if (!(fd->options & (FILE_SYNCHRONOUS_IO_ALERT | FILE_SYNCHRONOUS_IO_NONALERT)) && !fd->completion)
+        if (is_fd_overlapped( fd ) && !fd->completion)
         {
             fd->completion = get_completion_obj( current->process, req->chandle, IO_COMPLETION_MODIFY_STATE );
             fd->comp_key = req->ckey;
@@ -2639,7 +2645,7 @@ DECL_HANDLER(set_fd_completion_mode)
     struct fd *fd = get_handle_fd_obj( current->process, req->handle, 0 );
     if (fd)
     {
-        if (!(fd->options & (FILE_SYNCHRONOUS_IO_ALERT | FILE_SYNCHRONOUS_IO_NONALERT)))
+        if (is_fd_overlapped( fd ))
         {
             /* removing COMPLETION_SKIP_ON_SUCCESS is not allowed */
             fd->comp_flags |= req->flags & ( FILE_SKIP_COMPLETION_PORT_ON_SUCCESS
diff --git a/server/file.c b/server/file.c
index 37f7afe6553..8d39f303bd8 100644
--- a/server/file.c
+++ b/server/file.c
@@ -114,11 +114,6 @@ static const struct fd_ops file_fd_ops =
     default_fd_reselect_async     /* reselect_async */
 };
 
-static inline int is_overlapped( const struct file *file )
-{
-    return !(get_fd_options( file->fd ) & (FILE_SYNCHRONOUS_IO_ALERT | FILE_SYNCHRONOUS_IO_NONALERT));
-}
-
 /* create a file from a file descriptor */
 /* if the function fails the fd is closed */
 struct file *create_file_for_fd( int fd, unsigned int access, unsigned int sharing )
@@ -761,7 +756,7 @@ DECL_HANDLER(lock_file)
     if ((file = get_file_obj( current->process, req->handle, 0 )))
     {
         reply->handle = lock_fd( file->fd, req->offset, req->count, req->shared, req->wait );
-        reply->overlapped = is_overlapped( file );
+        reply->overlapped = is_fd_overlapped( file->fd );
         release_object( file );
     }
 }
diff --git a/server/file.h b/server/file.h
index 84cbc290374..a9581a7f6ea 100644
--- a/server/file.h
+++ b/server/file.h
@@ -88,6 +88,7 @@ extern struct fd *get_fd_object_for_mapping( struct fd *fd, unsigned int access,
 extern void *get_fd_user( struct fd *fd );
 extern void set_fd_user( struct fd *fd, const struct fd_ops *ops, struct object *user );
 extern unsigned int get_fd_options( struct fd *fd );
+extern int is_fd_overlapped( struct fd *fd );
 extern int get_unix_fd( struct fd *fd );
 extern int is_same_file_fd( struct fd *fd1, struct fd *fd2 );
 extern int is_fd_removable( struct fd *fd );