diff --git a/config.toml b/config.toml
index 5238f4b8..045f5695 100644
--- a/config.toml
+++ b/config.toml
@@ -1,5 +1,5 @@
 baseURL = "https://quarts-research-note.tomoyanonymous.github.io"
-languageCode = "en-us"
+languageCode = "ja-jp"
 relativeURLs = false
 disablePathToLower = true
 ignoreFiles = [