diff --git a/script/generate b/script/generate
index 47a77e40e..d850a5885 100755
--- a/script/generate
+++ b/script/generate
@@ -115,4 +115,4 @@ URLS=(https://content.googleapis.com/discovery/v1/apis/youtubePartner/v1/rest \
       https://monitoring.googleapis.com/\$discovery/rest?version=v3 \
 )
 
-echo 'a' | bundle exec bin/generate-api gen generated --from-discovery=true --names_out=$DIR/api_names_out.yaml --url=${URLS[*]}  --id=${API_IDS[*]}
+echo 'a' | bundle exec bin/generate-api gen generated --from_discovery=true --names_out=$DIR/api_names_out.yaml --url=${URLS[*]}  --id=${API_IDS[*]}