diff --git a/DDExamples/ILDExDet/CMakeLists.txt b/DDExamples/ILDExDet/CMakeLists.txt
index 1a81a15022252dba1e6a892e0a08e36087d290ef..050318cd7820b6372ddd068a75ed111785b91807 100644
--- a/DDExamples/ILDExDet/CMakeLists.txt
+++ b/DDExamples/ILDExDet/CMakeLists.txt
@@ -22,4 +22,5 @@ endif()
 
 add_library(ILDEx SHARED ${sources})
 target_link_libraries(ILDEx DD4hepCore)
+dd4hep_generate_rootmap(ILDEx)