diff --git a/install.sh b/install.sh
index 445abb3..f85d571 100644
--- a/install.sh
+++ b/install.sh
@@ -233,7 +233,7 @@ fi
 
 NODE_VERSION=${NODE_VERSION:-}
 NODEJS_VER=${NODEJS_VER:-}
-if [ -z "${NODEJS_VER:-}" ]; then
+if [ -n "$NODE_VERSION" ]; then
   NODEJS_VER=$NODE_VERSION
 fi