diff --git a/src/build/libroot/fs_darwin.cpp b/src/build/libroot/fs_darwin.cpp
index 86206df0f7..cfcd4d2be8 100644
--- a/src/build/libroot/fs_darwin.cpp
+++ b/src/build/libroot/fs_darwin.cpp
@@ -285,6 +285,9 @@ fstatat(int fd, const char *path, struct stat *st, int flag)
 		// CURRENTLY UNSUPPORTED
 		errno = ENOTSUP;
 		return -1;
+	} else if (flag != 0) {
+		errno = EINVAL;
+		return -1;
 	}
 
 	if (path != NULL && path[0] == '/') {