diff --git a/openbsc/include/openbsc/abis_nm.h b/openbsc/include/openbsc/abis_nm.h
index 00697a3..c237613 100644
--- a/openbsc/include/openbsc/abis_nm.h
+++ b/openbsc/include/openbsc/abis_nm.h
@@ -485,6 +485,12 @@
 	NM_AVSTATE_OK		= 0xff,
 };
 
+enum abis_nm_op_state {
+	NM_OPSTATE_DISABLED	= 1,
+	NM_OPSTATE_ENABLED	= 2,
+	NM_OPSTATE_NULL		= 0xff,
+};
+
 /* Section 9.4.13: Channel Combination */
 enum abis_nm_chan_comb {
 	NM_CHANC_TCHFull	= 0x00,	/* TCH/F + TCH/H + SACCH/TF */
diff --git a/openbsc/src/abis_nm.c b/openbsc/src/abis_nm.c
index 98683d3..c99ffcf 100644
--- a/openbsc/src/abis_nm.c
+++ b/openbsc/src/abis_nm.c
@@ -540,11 +540,11 @@
 const char *nm_opstate_name(u_int8_t os)
 {
 	switch (os) {
-	case 1:
+	case NM_OPSTATE_DISABLED:
 		return "Disabled";
-	case 2:
+	case NM_OPSTATE_ENABLED:
 		return "Enabled";
-	case 0xff:
+	case NM_OPSTATE_NULL:
 		return "NULL";
 	default:
 		return "RFU";