diff --git a/cmake_targets/CMakeLists.txt b/cmake_targets/CMakeLists.txt
index 17d921d4d987bac3f768635d40b15772203991d1..8ba602c25d248647570567cba9a113fbe29e4d07 100644
--- a/cmake_targets/CMakeLists.txt
+++ b/cmake_targets/CMakeLists.txt
@@ -462,6 +462,7 @@ add_boolean_option(ENABLE_SECURITY         True  "Enable LTE integrity and ciphe
 add_boolean_option(ENABLE_USE_MME          True  "eNB connected to MME (INTERFACE S1-C), not standalone eNB")
 add_boolean_option(NO_RRM                  True  "DO WE HAVE A RADIO RESSOURCE MANAGER: NO")
 add_boolean_option(USER_MODE True "????")
+add_boolean_option(RRC_DEFAULT_RAB_IS_AM False "set the RLC mode to AM for the default bearer")
 
 add_boolean_option(OAI_NW_DRIVER_TYPE_ETHERNET False "????")
 add_boolean_option(DISABLE_USE_NAS False "???")