diff --git a/lib/index.js b/lib/index.js
index 6bd6838d..5f1cea07 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -52,7 +52,8 @@ PG.prototype.cancel = function(config, client, query) {
   cancellingClient.cancel(client, query);
 };
 
-if (process.env.hasOwnProperty('NODE_PG_FORCE_NATIVE')) {
+var forceNative = Object.prototype.hasOwnProperty.call(process.env, 'NODE_PG_FORCE_NATIVE');
+if (forceNative) {
   module.exports = new PG(require(__dirname + '/native'));
 } else {
   module.exports = new PG(Client);