diff --git a/vlsisapd/CMakeLists.txt b/vlsisapd/CMakeLists.txt
index 82ae0166..e8733bc6 100644
--- a/vlsisapd/CMakeLists.txt
+++ b/vlsisapd/CMakeLists.txt
@@ -9,6 +9,10 @@ FIND_PACKAGE(PythonSitePackages REQUIRED)
 
 ADD_SUBDIRECTORY(agds)
 ADD_SUBDIRECTORY(cif)
-ADD_SUBDIRECTORY(openChams)
-ADD_SUBDIRECTORY(dtr)
+IF(IS_DIRECTORY openChams)
+  ADD_SUBDIRECTORY(openChams)
+ENDIF(IS_DIRECTORY openChams)
+IF(IS_DIRECTORY dtr)
+  ADD_SUBDIRECTORY(dtr)
+ENDIF(IS_DIRECTORY dtr)
 ADD_SUBDIRECTORY(cmake_modules)