diff --git a/run-tests.sh b/run-tests.sh
index 2fce4dd4..3cc120a7 100755
--- a/run-tests.sh
+++ b/run-tests.sh
@@ -22,7 +22,7 @@ curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.4/install.sh | b
 set -e
 cd $(dirname $0)
 
-if [ "x$node_versions" == "x" ] ; then
+if [ "x$node_versions" = "x" ] ; then
   node_versions="6 7 8"
 fi