diff --git a/sources/CMakeLists.txt b/sources/CMakeLists.txt
index c9ff987b..a3be7c79 100644
--- a/sources/CMakeLists.txt
+++ b/sources/CMakeLists.txt
@@ -1,4 +1,5 @@
 include(GenerateExportHeader)
+include(GNUInstallDirs)
 
 IF (NOT DEFINED CMAKE_MODULE_PATH)
   GET_FILENAME_COMPONENT(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../CMakeModules" ABSOLUTE)