-ADD_SUBDIRECTORY(${CLITK_SOURCE_DIR}/common ${PROJECT_BINARY_DIR}/common)
-ADD_SUBDIRECTORY(${CLITK_SOURCE_DIR}/tools ${PROJECT_BINARY_DIR}/tools)
-ADD_SUBDIRECTORY(${CLITK_SOURCE_DIR}/segmentation ${PROJECT_BINARY_DIR}/segmentation)
-ADD_SUBDIRECTORY(${CLITK_SOURCE_DIR}/registration ${PROJECT_BINARY_DIR}/registration)
+add_subdirectory(${CLITK_SOURCE_DIR}/common ${PROJECT_BINARY_DIR}/common)
+add_subdirectory(${CLITK_SOURCE_DIR}/tools ${PROJECT_BINARY_DIR}/tools)
+add_subdirectory(${CLITK_SOURCE_DIR}/segmentation ${PROJECT_BINARY_DIR}/segmentation)
+add_subdirectory(${CLITK_SOURCE_DIR}/registration ${PROJECT_BINARY_DIR}/registration)
+add_subdirectory(${CLITK_SOURCE_DIR}/cluster_tools ${PROJECT_BINARY_DIR}/cluster_tools)