diff --git a/gtsam/base/GenericValue.h b/gtsam/base/GenericValue.h
index e83a64ba9..17783c5b9 100644
--- a/gtsam/base/GenericValue.h
+++ b/gtsam/base/GenericValue.h
@@ -194,6 +194,11 @@ public:
 
 };
 
+// traits
+template <typename ValueType>
+struct traits<GenericValue<ValueType> >
+    : public Testable<GenericValue<ValueType> > {};
+
 // define Value::cast here since now GenericValue has been declared
 template<typename ValueType>
 const ValueType& Value::cast() const {