diff --git a/Triangulation_on_sphere_2/examples/Triangulation_on_sphere_2/CMakeLists.txt b/Triangulation_on_sphere_2/examples/Triangulation_on_sphere_2/CMakeLists.txt
index 3d3d7367f53..65ed31daad1 100644
--- a/Triangulation_on_sphere_2/examples/Triangulation_on_sphere_2/CMakeLists.txt
+++ b/Triangulation_on_sphere_2/examples/Triangulation_on_sphere_2/CMakeLists.txt
@@ -3,9 +3,15 @@ cmake_minimum_required(VERSION 3.1...3.23)
 project( Triangulation_on_sphere_2_Examples )
 
 find_package(CGAL REQUIRED COMPONENTS Core)
+find_package(LEDA QUIET)
 
 create_single_source_cgal_program( "triang_on_sphere.cpp" )
 create_single_source_cgal_program( "triang_on_sphere_range.cpp" )
-create_single_source_cgal_program( "triang_on_sphere_exact.cpp" )
 create_single_source_cgal_program( "triang_on_sphere_proj.cpp" )
 create_single_source_cgal_program( "triang_on_sphere_geo.cpp" )
+
+if (CGAL_Core_FOUND OR LEDA_FOUND)
+  create_single_source_cgal_program( "triang_on_sphere_exact.cpp" )
+else()
+  message("NOTICE: Some tests require CGAL_Core (or LEDA), and will not be compiled.")
+endif()
diff --git a/Triangulation_on_sphere_2/test/Triangulation_on_sphere_2/CMakeLists.txt b/Triangulation_on_sphere_2/test/Triangulation_on_sphere_2/CMakeLists.txt
index be2360314ef..1d27f25b35b 100644
--- a/Triangulation_on_sphere_2/test/Triangulation_on_sphere_2/CMakeLists.txt
+++ b/Triangulation_on_sphere_2/test/Triangulation_on_sphere_2/CMakeLists.txt
@@ -3,15 +3,21 @@ cmake_minimum_required(VERSION 3.1...3.23)
 project( Triangulation_on_sphere_2_Tests )
 
 find_package(CGAL REQUIRED COMPONENTS Core)
+find_package(LEDA QUIET)
 
 create_single_source_cgal_program( "test_dtos.cpp" )
 create_single_source_cgal_program( "test_dtos2_remove.cpp" )
-create_single_source_cgal_program( "test_dtos_degenerate_cases.cpp" )
 create_single_source_cgal_program( "test_dtos_illegal_points.cpp" )
 create_single_source_cgal_program( "test_dtos_projection_traits.cpp" )
 create_single_source_cgal_program( "test_dtos_traits.cpp" )
 create_single_source_cgal_program( "issue_8200.cpp" )
 
+if (CGAL_Core_FOUND OR LEDA_FOUND)
+  create_single_source_cgal_program( "test_dtos_degenerate_cases.cpp" )
+else()
+  message("NOTICE: Some tests require CGAL_Core (or LEDA), and will not be compiled.")
+endif()
+
 find_package(Eigen3 3.1.0 QUIET) #(requires 3.1.0 or greater)
 include(CGAL_Eigen3_support)
 if(TARGET CGAL::Eigen3_support)