diff --git a/Installation/src/CMakeLists.txt b/Installation/src/CMakeLists.txt
index 89c80f8e3c2..da125a00ca1 100644
--- a/Installation/src/CMakeLists.txt
+++ b/Installation/src/CMakeLists.txt
@@ -11,6 +11,13 @@ macro( configure_component DIR COMPONENT )
   endif()
 endmacro()
 
+if(COMMAND unset)
+  # Workaround: WITH_CGAL_Core can have been loaded from an old reference
+  # cache Then remove it from the cache, and re-add it only if CGAL_Core
+  # can be configured.
+  unset(WITH_CGAL_Core CACHE)
+endif()
+
 if(NOT CGAL_NO_CORE)
   configure_component( CGALCore    Core    )
 endif(NOT CGAL_NO_CORE)