diff --git a/lib/default/jsmn-shadinger-1.0/src/JsonParser.cpp b/lib/default/jsmn-shadinger-1.0/src/JsonParser.cpp
index 41b79c868..0668faa1a 100644
--- a/lib/default/jsmn-shadinger-1.0/src/JsonParser.cpp
+++ b/lib/default/jsmn-shadinger-1.0/src/JsonParser.cpp
@@ -408,6 +408,8 @@ void JsonParser::parse(char * json_in) {
   // TODO error checking
   if (_token_len >= 0) {
     postProcess(json_len);
+  } else {
+    this->free();   // invalid JSON
   }
 }