diff --git a/packages/app.sql b/packages/app.sql
index 59f3b19..575db71 100644
--- a/packages/app.sql
+++ b/packages/app.sql
@@ -242,7 +242,12 @@ CREATE OR REPLACE PACKAGE BODY app AS
         RETURN out_lang;
     EXCEPTION
     WHEN NO_DATA_FOUND THEN
-        RETURN REPLACE(UPPER(SUBSTR(OWA_UTIL.GET_CGI_ENV('HTTP_ACCEPT_LANGUAGE'), 1, 2)), 'CS', 'CZ');
+        BEGIN
+            RETURN REPLACE(UPPER(SUBSTR(OWA_UTIL.GET_CGI_ENV('HTTP_ACCEPT_LANGUAGE'), 1, 2)), 'CS', 'CZ');
+        EXCEPTION
+        WHEN OTHERS THEN
+            RETURN 'EN';
+        END;
     END;