diff --git a/CGAL_ipelets/demo/CGAL_ipelets/cgal_test_with_cmake b/CGAL_ipelets/demo/CGAL_ipelets/cgal_test_with_cmake
index e7093a67bcd..e3ea1cc9564 100755
--- a/CGAL_ipelets/demo/CGAL_ipelets/cgal_test_with_cmake
+++ b/CGAL_ipelets/demo/CGAL_ipelets/cgal_test_with_cmake
@@ -180,6 +180,6 @@ fi
 #
 if [ -n "${NEED_CLEAN}" ]; then 
   if ! ( uname | grep -q "CYGWIN" ) ; then
-    ${MAKE_CMD} -fMakefile clean
+    ${MAKE_CMD} -fMakefile clean || true
   fi
 fi
diff --git a/Mesh_3/demo/Mesh_3/cgal_test_with_cmake b/Mesh_3/demo/Mesh_3/cgal_test_with_cmake
index 8b3e2a2d4a7..f84ac21c545 100755
--- a/Mesh_3/demo/Mesh_3/cgal_test_with_cmake
+++ b/Mesh_3/demo/Mesh_3/cgal_test_with_cmake
@@ -149,6 +149,6 @@ fi
 #
 if [ -n "${NEED_CLEAN}" ]; then
   if ! ( uname | grep -q "CYGWIN" ) ; then
-    ${MAKE_CMD} -fMakefile clean
+    ${MAKE_CMD} -fMakefile clean || true
   fi
 fi
diff --git a/Polyhedron/demo/Polyhedron/cgal_test_with_cmake b/Polyhedron/demo/Polyhedron/cgal_test_with_cmake
index a1ae9d9b49e..c11be271e54 100755
--- a/Polyhedron/demo/Polyhedron/cgal_test_with_cmake
+++ b/Polyhedron/demo/Polyhedron/cgal_test_with_cmake
@@ -182,6 +182,6 @@ fi
 #
 if [ -n "${NEED_CLEAN}" ]; then 
   if ! ( uname | grep -q "CYGWIN" ) ; then
-    ${MAKE_CMD} -fMakefile clean
+    ${MAKE_CMD} -fMakefile clean || true
   fi
 fi