diff --git a/gui/CMakeLists.txt b/gui/CMakeLists.txt
index 9d58c5cd34cf66f0330781ba3ef1196f1033495c..b3fa09a62138a5a2f0c03cf2253b38f66e065b49 100644
--- a/gui/CMakeLists.txt
+++ b/gui/CMakeLists.txt
@@ -1,4 +1,4 @@
-INCLUDE_DIRECTORIES( ${CLASS_HEADERS_DIR} )
+INCLUDE_DIRECTORIES( ${CLASS_HEADERS_DIR_INCLUDE} )
 add_executable (CLASSgui CLASSGui.cxx CLASSPlotElement.cxx CLASSWin.cxx CLASSRead.cxx)
 target_link_libraries(CLASSgui CLASSpkg)
 
diff --git a/source/include/CMakeLists.txt b/source/include/CMakeLists.txt
index 9f2866b234c42e4178c9a9df3f7dded175acce73..0eaac8a56171a7eabd0c80215abc5e23d123fbea 100644
--- a/source/include/CMakeLists.txt
+++ b/source/include/CMakeLists.txt
@@ -3,7 +3,7 @@
 # ----------------------------------------------------------
 
 # include directories 
-SET( CLASS_HEADERS_DIR ${CMAKE_CURRENT_SOURCE_DIR} CACHE INTERNAL "")
+SET( CLASS_HEADERS_DIR_INCLUDE ${CMAKE_CURRENT_SOURCE_DIR} CACHE INTERNAL "")