diff --git a/code/backends/JSONBackend.php b/code/backends/JSONBackend.php
index 8943d27..ced2356 100755
--- a/code/backends/JSONBackend.php
+++ b/code/backends/JSONBackend.php
@@ -55,7 +55,7 @@ abstract public function matchOnInt();
      * @return array
      * @throws JSONTextException
      */
-    abstract function matchOnStr();
+    abstract public function matchOnStr();
 
     /**
      * Match on RDBMS-specific path operator. If >1 matches are found, an indexed array of all matches is returned.