Index: /trunk/FACT++/CMakeLists.txt
===================================================================
--- /trunk/FACT++/CMakeLists.txt	(revision 19854)
+++ /trunk/FACT++/CMakeLists.txt	(revision 19855)
@@ -279,5 +279,5 @@
 
    # Is this is a local or a global installation?
-   IF(ENV{ROOTSYS})
+   IF(DEFINED ENV{ROOTSYS})
       IF(ROOTSYS AND NOT ROOTSYS STREQUAL "$ENV{ROOTSYS}")
          MESSAGE(WARNING