diff --git a/.dir-locals.el b/.dir-locals.el
index 37a0774a..7ea6db3f 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -1,2 +1,3 @@
-((cpp-mode . ((mode . clang-format-on-save))))
-((c-mode . ((mode . c++))))
+((c++-mode . (mode . clang-format-on-save))))
+
+((c-mode . ((mode c++-mode))))