diff --git a/src/main/java/indi/yoyicue/machinetranslators/TencentTranslate.java b/src/main/java/indi/yoyicue/machinetranslators/TencentTranslate.java
index b2bcb3a..6693407 100644
--- a/src/main/java/indi/yoyicue/machinetranslators/TencentTranslate.java
+++ b/src/main/java/indi/yoyicue/machinetranslators/TencentTranslate.java
@@ -85,7 +85,7 @@ private String tmtLang(Language language) {
         } else if (lang.equalsIgnoreCase("ko")) {
             return "kr";
         } else {
-            return language.getLanguageCode();
+            return language.getLanguageCode().toLowerCase();
         }
 
     }
@@ -115,4 +115,4 @@ protected void onConfirm() {
         dialog.panel.temporaryCheckBox.setSelected(isCredentialStoredTemporarily(PROPERTY_API_SECRET_KEY));
         dialog.show();
     }
-}
\ No newline at end of file
+}