diff --git a/firmware/common/dir.h b/firmware/common/dir.h
index 83d4bfec98..1aa3476fe0 100644
--- a/firmware/common/dir.h
+++ b/firmware/common/dir.h
@@ -29,6 +29,8 @@ struct dirent {
 };
 
 extern DIR* opendir(char* name);
+extern int closedir(DIR* dir);
+
 extern struct dirent* readdir(DIR* dir);
 
 #endif