diff --git a/include/osmocom/gsm/protocol/gsm_12_21.h b/include/osmocom/gsm/protocol/gsm_12_21.h
index 694df93..b1725d5 100644
--- a/include/osmocom/gsm/protocol/gsm_12_21.h
+++ b/include/osmocom/gsm/protocol/gsm_12_21.h
@@ -486,6 +486,8 @@
 	NM_ATT_BS11_ANT_TYPE		= 0xf4,
 	NM_ATT_BS11_PLL_MODE		= 0xfc,
 	NM_ATT_BS11_PASSWORD		= 0xfd,
+
+	NM_ATT_O_REDUCEPOWER		= 0x01,
 };
 #define NM_ATT_BS11_FILE_DATA	NM_ATT_EVENT_TYPE