diff --git a/scripts/lib/custom-docker-build b/scripts/lib/custom-docker-build
index 54c0c26..11a4a69 100755
--- a/scripts/lib/custom-docker-build
+++ b/scripts/lib/custom-docker-build
@@ -161,9 +161,6 @@ function print_node_args() {
 
 function print_yarn_args() {
     case "$1" in
-        1.12) YARN_INSTALL_VERSION=1.12.3 ;;
-        1.16) YARN_INSTALL_VERSION=1.16.0 ;;
-        1.21) YARN_INSTALL_VERSION=1.21.1 ;;
         1.22) YARN_INSTALL_VERSION=1.22.19 ;;
         *) fail "Unknown yarn version $1" ;;
     esac