diff --git a/lib/walletutils.js b/lib/walletutils.js
index 6707a63..78f4c71 100644
--- a/lib/walletutils.js
+++ b/lib/walletutils.js
@@ -32,7 +32,11 @@ WalletUtils.signMessage = function(text, privKey) {
 
 
 WalletUtils.verifyMessage = function(text, signature, pubKey) {
-  $.checkArgument(signature, text, pubKey);
+  $.checkArgument(text, pubKey);
+
+  if (!signature)
+    return false;
+
   var pub = new PublicKey(pubKey);
   var hash = WalletUtils.hashMessage(text);