diff --git a/utils/update_version.js b/utils/update_version.js
index a0838672e3..595dcc4440 100755
--- a/utils/update_version.js
+++ b/utils/update_version.js
@@ -47,7 +47,7 @@ if (version === '--next') {
   const packageJSON = require('../package.json');
   version = packageJSON.version;
   const dashIndex = version.indexOf('-');
-  if (dashIndex === -1)
+  if (dashIndex !== -1)
     version = version.substring(0, dashIndex);
   version += '-next.' + Date.now();
   console.log('Setting version to ' + version);