diff --git a/gtsam/base/GenericValue.h b/gtsam/base/GenericValue.h
index 5d46e7fbe..9c846f739 100644
--- a/gtsam/base/GenericValue.h
+++ b/gtsam/base/GenericValue.h
@@ -212,8 +212,7 @@ public:
 
     /// Return run-time dimensionality
     virtual size_t dim() const {
-      // need functional form here since the dimension may be dynamic
-      return traits_x<T>::GetDimension(GenericValue<T>::value());
+      return traits_x<T>::GetDimension(value_);
     }
 
     /// Assignment operator