diff --git a/cmake/DD4hep.cmake b/cmake/DD4hep.cmake
index 4b101c9103d46c91997929c3c7e4a29febf1cc43..52b139e052ac45b5f0968f90765ee9f6eb17adbb 100644
--- a/cmake/DD4hep.cmake
+++ b/cmake/DD4hep.cmake
@@ -7,7 +7,7 @@ function(dd4hep_generate_rootmap library)
   find_package(ROOT QUIET)
   set(rootmapfile ${CMAKE_SHARED_MODULE_PREFIX}${library}.rootmap)
 
-  set(libname ${CMAKE_SHARED_MODULE_PREFIX}${library}${CMAKE_SHARED_MODULE_SUFFIX})
+  set(libname ${CMAKE_SHARED_MODULE_PREFIX}${library}${CMAKE_SHARED_LIBRARY_SUFFIX})
   add_custom_command(OUTPUT ${rootmapfile}
                      COMMAND cd ${LIBRARY_OUTPUT_PATH} && genmap
 		             ${ROOT_genmap_CMD} -i ${libname} -o ${rootmapfile}