diff --git a/src/python/gudhi/_ripser.cc b/src/python/gudhi/_ripser.cc
index 97e804fd4d..1fb24aab23 100644
--- a/src/python/gudhi/_ripser.cc
+++ b/src/python/gudhi/_ripser.cc
@@ -28,7 +28,7 @@ PYBIND11_MAKE_OPAQUE(Vf);
 PYBIND11_MAKE_OPAQUE(Vd);
 
 template<class T>struct Numpy_euclidean {
-  typedef Tag_other category;
+  typedef Tag_other Category;
   typedef int vertex_t;
   typedef T value_t;
 
@@ -47,7 +47,7 @@ template<class T>struct Numpy_euclidean {
 };
 
 template<class T>struct Full {
-  typedef Tag_dense category;
+  typedef Tag_dense Category;
   typedef int vertex_t;
   typedef T value_t;
   decltype(std::declval<py::array_t<T>&>().template unchecked<2>()) data;
@@ -122,7 +122,7 @@ py::list lower(py::object low_mat, int max_dimension, double max_edge_length, un
   };
 
   std::optional<py::gil_scoped_release> release_local(std::in_place);
-  compressed_distance_matrix<DParams<int, double>, LOWER_TRIANGULAR> dist(std::move(distances));
+  Compressed_distance_matrix<DParams<int, double>, LOWER_TRIANGULAR> dist(std::move(distances));
   release_local.reset();
 
   return doit(std::move(dist), max_dimension, max_edge_length, homology_coeff_field);
@@ -139,7 +139,7 @@ py::list sparse(py::array_t<V> is_, py::array_t<V> js_, py::array_t<T> fs_, int
     throw std::runtime_error("vertices and filtrations must have the same shape");
 
   typedef DParams<V, T> P;
-  typedef sparse_distance_matrix<P> Dist;
+  typedef Sparse_distance_matrix<P> Dist;
   typedef typename Dist::vertex_diameter_t vertex_diameter_t;
 
   std::optional<py::gil_scoped_release> release_local(std::in_place);