diff --git a/src/hdnode.js b/src/hdnode.js
index 226416d..9f0828e 100644
--- a/src/hdnode.js
+++ b/src/hdnode.js
@@ -167,7 +167,7 @@ HDNode.prototype.toBase58 = function(isPrivate) {
 
 // FIXME: remove in 2.x.y
 HDNode.prototype.toBuffer = function(isPrivate, __ignoreDeprecation) {
-  if (isPrivate == undefined) {
+  if (isPrivate === undefined) {
     isPrivate = !!this.privKey
 
   // FIXME: remove in 2.x.y