diff --git a/tasks/mm0/src/file.c b/tasks/mm0/src/file.c
index 4e253b9..0eca30b 100644
--- a/tasks/mm0/src/file.c
+++ b/tasks/mm0/src/file.c
@@ -410,7 +410,10 @@ int do_close(struct tcb *task, int fd)
 
 	/* Reduce file's opener count */
 	if (!(--task->files->fd[fd].vmfile->openers))
-		vm_file_delete(task->files->fd[fd].vmfile);
+		/* No openers left, check any mappers */
+		if (!task->files->fd[fd].vmfile->vm_obj.nlinks)
+			/* No links or openers, delete the file */
+			vm_file_delete(task->files->fd[fd].vmfile);
 
 	task->files->fd[fd].vnum = 0;
 	task->files->fd[fd].cursor = 0;
diff --git a/tasks/mm0/src/task.c b/tasks/mm0/src/task.c
index 774d78f..d9bf9ae 100644
--- a/tasks/mm0/src/task.c
+++ b/tasks/mm0/src/task.c
@@ -219,8 +219,13 @@ int copy_tcb(struct tcb *to, struct tcb *from, unsigned int flags)
 		to->files = from->files;
 		to->files->tcb_refs++;
 	} else {
-	       	/* Copy all file descriptors */
+	       	/* Bulk copy all file descriptors */
 		memcpy(to->files, from->files, sizeof(*to->files));
+
+		/* Increase refcount for all open files */
+		for (int i = 0; i < TASK_FILES_MAX; i++)
+			if (to->files->fd[i].vmfile)
+				to->files->fd[i].vmfile->openers++;
 	}
 
 	return 0;