diff --git a/Eigen/src/Core/CoreEvaluators.h b/Eigen/src/Core/CoreEvaluators.h
index 1541f940e..9b6a442e5 100644
--- a/Eigen/src/Core/CoreEvaluators.h
+++ b/Eigen/src/Core/CoreEvaluators.h
@@ -96,7 +96,7 @@ struct evaluator<const T>
 // ---------- base class for all evaluators ----------
 
 template<typename ExpressionType>
-struct evaluator_base
+struct evaluator_base : public noncopyable
 {
   // TODO Check whether nestedType is really needed:
   //      As long as evaluator are non-copyable, there is no reason to make it different.