diff --git a/Makefile b/Makefile
index f071f4b58e..b4efc99975 100644
--- a/Makefile
+++ b/Makefile
@@ -576,7 +576,7 @@ pot: $(UI_BUILD_FLAG_FILE)
 po: $(UI_BUILD_FLAG_FILE)
 	$(NPM_BIN) --prefix awx/ui --loglevel warn run extract-strings -- --clean
 
-LANG = "en-us"
+LANG = "en_us"
 ## generate API django .pot .po
 messages:
 	@if [ "$(VENV_BASE)" ]; then \