diff --git a/contrib/kolibri-libc/source/include/ksys.h b/contrib/kolibri-libc/source/include/ksys.h
index 046cff74c6..aba7ae940d 100644
--- a/contrib/kolibri-libc/source/include/ksys.h
+++ b/contrib/kolibri-libc/source/include/ksys.h
@@ -951,7 +951,7 @@ int not_optimized _ksys_exec(char *app_name, char *args)
 }
 
 static inline
-int _ksys_mkdir(const char *path)
+int not_optimized _ksys_mkdir(const char *path)
 {
     ksys70_t dir_opt;
     dir_opt.p00 = 9;
@@ -987,4 +987,4 @@ void _ksys_shm_close(char *shm_name)
 }
 #endif
 
-#endif // _KSYS_H_
\ No newline at end of file
+#endif // _KSYS_H_