diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06877cfe..5c0c6aad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,11 +36,18 @@ endif()
 
 set(Boost_USE_STATIC_LIBS ON)
 
+get_directory_property(PSEMEK_PARENT_DIRECTORY PARENT_DIRECTORY)
+
 add_subdirectory(package)
 add_subdirectory(tools)
 add_subdirectory(libs)
 
-psemek_add_library(psemek EXCLUDE_FROM_ALL todo.md)
+set(PSEMEK_SOURCES)
+if(NOT PSEMEK_PARENT_DIRECTORY)
+	list(APPEND PSEMEK_SOURCES todo.md)
+endif()
+
+psemek_add_library(psemek EXCLUDE_FROM_ALL ${PSEMEK_SOURCES})
 target_link_libraries(psemek INTERFACE ${PSEMEK_LIBRARIES})
 set_target_properties(psemek PROPERTIES LINKER_LANGUAGE CXX)