diff --git a/src/PHPCR/Util/CND/Parser/CndParser.php b/src/PHPCR/Util/CND/Parser/CndParser.php
index 6173cc9..94c5b01 100644
--- a/src/PHPCR/Util/CND/Parser/CndParser.php
+++ b/src/PHPCR/Util/CND/Parser/CndParser.php
@@ -672,6 +672,12 @@ protected function parseCndString()
 
         while (true) {
             $token = $this->tokenQueue->peek();
+
+            // If there are no more tokens, break
+            if (!$token) {
+                break;
+            }
+
             $type = $token->getType();
             $data = $token->getData();