diff --git a/src/Persistence_matrix/include/gudhi/utilities/Multi_field.h b/src/Persistence_matrix/include/gudhi/Fields/Multi_field.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Multi_field.h
rename to src/Persistence_matrix/include/gudhi/Fields/Multi_field.h
diff --git a/src/Persistence_matrix/include/gudhi/utilities/Multi_field_shared.h b/src/Persistence_matrix/include/gudhi/Fields/Multi_field_shared.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Multi_field_shared.h
rename to src/Persistence_matrix/include/gudhi/Fields/Multi_field_shared.h
diff --git a/src/Persistence_matrix/include/gudhi/utilities/Multi_field_small.h b/src/Persistence_matrix/include/gudhi/Fields/Multi_field_small.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Multi_field_small.h
rename to src/Persistence_matrix/include/gudhi/Fields/Multi_field_small.h
diff --git a/src/Persistence_matrix/include/gudhi/utilities/Multi_field_small_shared.h b/src/Persistence_matrix/include/gudhi/Fields/Multi_field_small_shared.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Multi_field_small_shared.h
rename to src/Persistence_matrix/include/gudhi/Fields/Multi_field_small_shared.h
diff --git a/src/Persistence_matrix/include/gudhi/utilities/Z2_field.h b/src/Persistence_matrix/include/gudhi/Fields/Z2_field.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Z2_field.h
rename to src/Persistence_matrix/include/gudhi/Fields/Z2_field.h
diff --git a/src/Persistence_matrix/include/gudhi/utilities/Zp_field.h b/src/Persistence_matrix/include/gudhi/Fields/Zp_field.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Zp_field.h
rename to src/Persistence_matrix/include/gudhi/Fields/Zp_field.h
diff --git a/src/Persistence_matrix/include/gudhi/utilities/Zp_field_shared.h b/src/Persistence_matrix/include/gudhi/Fields/Zp_field_shared.h
similarity index 100%
rename from src/Persistence_matrix/include/gudhi/utilities/Zp_field_shared.h
rename to src/Persistence_matrix/include/gudhi/Fields/Zp_field_shared.h
diff --git a/src/Persistence_matrix/include/gudhi/persistence_matrix_options.h b/src/Persistence_matrix/include/gudhi/persistence_matrix_options.h
index be02deef07..e09851d380 100644
--- a/src/Persistence_matrix/include/gudhi/persistence_matrix_options.h
+++ b/src/Persistence_matrix/include/gudhi/persistence_matrix_options.h
@@ -16,7 +16,7 @@
 #ifndef OPTIONS_INCLUDED
 #define OPTIONS_INCLUDED
 
-#include "utilities/Z2_field.h"
+#include "Fields/Z2_field.h"
 
 namespace Gudhi {
 namespace persistence_matrix {
diff --git a/src/Persistence_matrix/test/Persistence_matrix_column_compression_unit_test.cpp b/src/Persistence_matrix/test/Persistence_matrix_column_compression_unit_test.cpp
index 7fec796640..491690b0ae 100644
--- a/src/Persistence_matrix/test/Persistence_matrix_column_compression_unit_test.cpp
+++ b/src/Persistence_matrix/test/Persistence_matrix_column_compression_unit_test.cpp
@@ -23,9 +23,9 @@
 
 #include "gudhi/matrix.h"
 #include "gudhi/persistence_matrix_options.h"
-#include "gudhi/utilities/Z2_field.h"
-#include "gudhi/utilities/Zp_field.h"
-// #include "gudhi/utilities/utilities.h"
+#include "gudhi/Fields/Z2_field.h"
+#include "gudhi/Fields/Zp_field.h"
+// #include "gudhi/Fields/utilities.h"
 
 using Gudhi::persistence_matrix::Z2_field_element;
 using Gudhi::persistence_matrix::Zp_field_element;
diff --git a/src/Persistence_matrix/test/Persistence_matrix_columns_test.cpp b/src/Persistence_matrix/test/Persistence_matrix_columns_test.cpp
index d16540dd09..919fd03428 100644
--- a/src/Persistence_matrix/test/Persistence_matrix_columns_test.cpp
+++ b/src/Persistence_matrix/test/Persistence_matrix_columns_test.cpp
@@ -21,8 +21,8 @@
 #include <set>
 #include <utility>
 
-#include "gudhi/utilities/Zp_field.h"
-#include "gudhi/utilities/utilities.h"
+#include "gudhi/Fields/Zp_field.h"
+// #include "gudhi/Fields/utilities.h"
 // #include "gudhi/column_types/row_access.h"
 // #include "gudhi/column_types/cell.h"
 #include "gudhi/Persistence_matrix/columns/cell_types.h"
@@ -132,9 +132,9 @@ using Gudhi::persistence_matrix::Cell_field_element;
 
 using Gudhi::persistence_matrix::Row_access;
 using Gudhi::persistence_matrix::Dummy_row_access;
-using Gudhi::persistence_matrix::dimension_type;
-using Gudhi::persistence_matrix::matrix_row_tag;
-using Gudhi::persistence_matrix::matrix_column_tag;
+// using Gudhi::persistence_matrix::dimension_type;
+// using Gudhi::persistence_matrix::matrix_row_tag;
+// using Gudhi::persistence_matrix::matrix_column_tag;
 using Gudhi::persistence_matrix::Column_dimension_holder;
 using Gudhi::persistence_matrix::Dummy_dimension_holder;
 using Gudhi::persistence_matrix::Chain_column_extra_properties;
@@ -241,8 +241,8 @@ struct Mini_matrix{
 
 	static constexpr bool isNonBasic = !Options::is_basic;
 
-	// struct matrix_row_tag;
-	// struct matrix_column_tag;
+	struct matrix_row_tag;
+	struct matrix_column_tag;
 
 	using base_hook_matrix_row = boost::intrusive::list_base_hook<
 				boost::intrusive::tag < matrix_row_tag >
diff --git a/src/Persistence_matrix/test/Persistence_matrix_common_unit_test.cpp b/src/Persistence_matrix/test/Persistence_matrix_common_unit_test.cpp
index a42eba4131..f6153c56a2 100644
--- a/src/Persistence_matrix/test/Persistence_matrix_common_unit_test.cpp
+++ b/src/Persistence_matrix/test/Persistence_matrix_common_unit_test.cpp
@@ -23,9 +23,9 @@
 
 #include "gudhi/matrix.h"
 #include "gudhi/persistence_matrix_options.h"
-#include "gudhi/utilities/Z2_field.h"
-#include "gudhi/utilities/Zp_field.h"
-// #include "gudhi/utilities/utilities.h"
+#include "gudhi/Fields/Z2_field.h"
+#include "gudhi/Fields/Zp_field.h"
+// #include "gudhi/Fields/utilities.h"
 
 using Gudhi::persistence_matrix::Z2_field_element;
 using Gudhi::persistence_matrix::Zp_field_element;
diff --git a/src/Persistence_matrix/test/Persistence_matrix_field_unit_test.cpp b/src/Persistence_matrix/test/Persistence_matrix_field_unit_test.cpp
index dd5f5e206c..c24cd513f7 100644
--- a/src/Persistence_matrix/test/Persistence_matrix_field_unit_test.cpp
+++ b/src/Persistence_matrix/test/Persistence_matrix_field_unit_test.cpp
@@ -12,13 +12,13 @@
 #define BOOST_TEST_MODULE "persistence_matrix"
 #include <boost/test/unit_test.hpp>
 
-#include "gudhi/utilities/Z2_field.h"
-#include "gudhi/utilities/Zp_field.h"
-#include "gudhi/utilities/Zp_field_shared.h"
-#include "gudhi/utilities/Multi_field.h"
-#include "gudhi/utilities/Multi_field_small.h"
-#include "gudhi/utilities/Multi_field_shared.h"
-#include "gudhi/utilities/Multi_field_small_shared.h"
+#include "gudhi/Fields/Z2_field.h"
+#include "gudhi/Fields/Zp_field.h"
+#include "gudhi/Fields/Zp_field_shared.h"
+#include "gudhi/Fields/Multi_field.h"
+#include "gudhi/Fields/Multi_field_small.h"
+#include "gudhi/Fields/Multi_field_shared.h"
+#include "gudhi/Fields/Multi_field_small_shared.h"
 
 using Gudhi::persistence_matrix::Z2_field_element;
 using Gudhi::persistence_matrix::Zp_field_element;
diff --git a/src/Persistence_matrix/test/Persistence_matrix_specialized_unit_test.cpp b/src/Persistence_matrix/test/Persistence_matrix_specialized_unit_test.cpp
index d685cecf7e..ea41d29b9b 100644
--- a/src/Persistence_matrix/test/Persistence_matrix_specialized_unit_test.cpp
+++ b/src/Persistence_matrix/test/Persistence_matrix_specialized_unit_test.cpp
@@ -23,9 +23,9 @@
 
 #include "gudhi/matrix.h"
 #include "gudhi/persistence_matrix_options.h"
-#include "gudhi/utilities/Z2_field.h"
-#include "gudhi/utilities/Zp_field.h"
-// #include "gudhi/utilities/utilities.h"
+#include "gudhi/Fields/Z2_field.h"
+#include "gudhi/Fields/Zp_field.h"
+// #include "gudhi/Fields/utilities.h"
 
 using Gudhi::persistence_matrix::Z2_field_element;
 using Gudhi::persistence_matrix::Zp_field_element;