diff --git a/CMakeLists.txt b/CMakeLists.txt
index 86be481..9fa686c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -124,7 +124,7 @@ find_package(Belr 5.3.0 REQUIRED)
 if(ENABLE_ADVANCED_IM)
 	bc_find_package(XercesC XercesC::XercesC xerces-c REQUIRED)
 	set(HAVE_ADVANCED_IM 1)
-	set(LIBXSD_INCLUDE_DIRS "${PROJECT_SOURCE_DIR}/libxsd")
+	set(LIBXSD_INCLUDE_DIRS "${CMAKE_INSTALL_FULL_INCLUDEDIR}")
 endif()
 
 if(ENABLE_SRTP)