diff --git a/locales/es-US/default.po b/locales/es-US/default.po
index 0dc36e5..7effda0 100644
--- a/locales/es-US/default.po
+++ b/locales/es-US/default.po
@@ -1,7 +1,7 @@
 msgid ""
 msgstr ""
 "Content-Type: text/plain; charset=UTF-8\n"
-"Language: es_US\n"
+"Language: es-US\n"
 "Plural-Forms: nplurals=2; plural=(n != 1);\n"
 
 msgid "Jan _2 15:04:05 MST 2006"