diff --git a/include/eigenpy/eigen-allocator.hpp b/include/eigenpy/eigen-allocator.hpp
index 243c1d3d4d1ba870c965af770cd11434cbf5b499..a186d828cfbb97048a40222fe9a5a462ab810bf4 100644
--- a/include/eigenpy/eigen-allocator.hpp
+++ b/include/eigenpy/eigen-allocator.hpp
@@ -79,7 +79,7 @@ namespace eigenpy
                       const Eigen::MatrixBase<MatrixOut> & /*dest*/)
       {
         // do nothing
-        assert("Must never happened");
+        assert(false && "Must never happened");
       }
     };