diff --git a/ext/tk/MANUAL_tcltklib.jp b/ext/tk/MANUAL_tcltklib.ja
similarity index 100%
rename from ext/tk/MANUAL_tcltklib.jp
rename to ext/tk/MANUAL_tcltklib.ja
diff --git a/ext/tk/old-README.tcltklib.jp b/ext/tk/old-README.tcltklib.ja
similarity index 100%
rename from ext/tk/old-README.tcltklib.jp
rename to ext/tk/old-README.tcltklib.ja