diff --git a/Envelope_3/test/Envelope_3/CMakeLists.txt b/Envelope_3/test/Envelope_3/CMakeLists.txt
index b087dba97ef..c5eb08f87fa 100644
--- a/Envelope_3/test/Envelope_3/CMakeLists.txt
+++ b/Envelope_3/test/Envelope_3/CMakeLists.txt
@@ -6,11 +6,10 @@ project(Envelope_3_Tests)
 
 find_package(CGAL REQUIRED COMPONENTS Core)
 
-# create a target per cppfile
-file(
-  GLOB cppfiles
-  RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
-  ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp)
-foreach(cppfile ${cppfiles})
-  create_single_source_cgal_program("${cppfile}")
-endforeach()
+create_single_source_cgal_program("triangles_test.cpp")
+
+if (CGAL_Core_FOUND)
+  create_single_source_cgal_program("spheres_test.cpp")
+else()
+  message("NOTICE: A test requires CGAL_Core, and will not be compiled.")
+endif()
diff --git a/Envelope_3/test/Envelope_3/spheres_test.cpp b/Envelope_3/test/Envelope_3/spheres_test.cpp
index 7fd2634e1a9..2d45e12526a 100644
--- a/Envelope_3/test/Envelope_3/spheres_test.cpp
+++ b/Envelope_3/test/Envelope_3/spheres_test.cpp
@@ -5,7 +5,7 @@
 
 int main ()
 {
-  bool UNTESTED_TRAITS_AS_CORE_IS_NOT_ISTALLED;
+  bool UNTESTED_TRAITS_AS_CORE_IS_NOT_INSTALLED;
   std::cout << std::endl
             << "WARNING: Core is not installed, "
             << "skipping the test ..."