diff --git a/config.toml b/config.toml
index 2747fa8b..b0b0d7e3 100644
--- a/config.toml
+++ b/config.toml
@@ -1,6 +1,6 @@
 title = "Matsuura Tomoya Research Note"
 baseURL = "https://.tomoyanonymous.github.io/quarts-research-note"
-languageCode = "ja-jp"
+languageCode = "ja"
 relativeURLs = false
 disablePathToLower = true
 ignoreFiles = [