diff --git a/wadsrc/static/menudef.txt b/wadsrc/static/menudef.txt
index 6d08e0cd6..f56157800 100644
--- a/wadsrc/static/menudef.txt
+++ b/wadsrc/static/menudef.txt
@@ -2725,6 +2725,7 @@ OptionString "LanguageOptions"
 	"de", "Deutsch (German)"
 	"es", "Español (España) (Castilian Spanish)"
 	"esm", "Español (Latino) (Latin American Spanish)"
+	"eo", "Esperanto"
 	"fi", "Suomi (Finnish)"
 	"fr", "Français (French)"
 	"it", "Italiano (Italian)"