diff --git a/lang/py/build.sh b/lang/py/build.sh
index 1c0f188f14c..83eafe16cfa 100755
--- a/lang/py/build.sh
+++ b/lang/py/build.sh
@@ -18,7 +18,7 @@
 set -e
 
 usage() {
-  echo "Usage: $0 {clean|dist|interop-data-generate|interop-data-test|lint|test}"
+  echo "Usage: $0 {clean|dist|doc|interop-data-generate|interop-data-test|lint|test}"
   exit 1
 }