diff --git a/include/valijson/schema_parser.hpp b/include/valijson/schema_parser.hpp
index 12915f9..e3d0c7f 100644
--- a/include/valijson/schema_parser.hpp
+++ b/include/valijson/schema_parser.hpp
@@ -48,7 +48,7 @@ public:
     /**
      * @brief  Release memory associated with custom ConstraintBuilders
      */
-    ~SchemaParser()
+   virtual ~SchemaParser()
     {
         for (const auto& entry : constraintBuilders) {
             delete entry.second;