diff --git a/src/schema.hpp b/src/schema.hpp
index b103fd4..00586b5 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -41,7 +41,7 @@
 };
 
 
-class InvalidNodeException {
+class InvalidNodeException : std::exception {
 };
 
 /*! \class Schema