diff --git a/library/RSL_Types.ttcn b/library/RSL_Types.ttcn
index 2d9c92e..b81bbbd 100644
--- a/library/RSL_Types.ttcn
+++ b/library/RSL_Types.ttcn
@@ -364,18 +364,30 @@
 	}
 
 	/* 9.3.7 */
+	type enumerated RSL_AlgId {
+		RSL_ALG_ID_A5_0 ('00000001'B),
+		RSL_ALG_ID_A5_1 ('00000010'B),
+		RSL_ALG_ID_A5_2 ('00000011'B),
+		RSL_ALG_ID_A5_3 ('00000100'B),
+		RSL_ALG_ID_A5_4 ('00000101'B),
+		RSL_ALG_ID_A5_5 ('00000110'B),
+		RSL_ALG_ID_A5_6 ('00000111'B),
+		RSL_ALG_ID_A5_7 ('00001000'B)
+	} with { variant "FIELDLENGTH(8)" };
 	type record RSL_IE_EncryptionInfo {
 		uint8_t		len,
-		OCT1		alg_id,
+		RSL_AlgId	alg_id,
 		octetstring	key
 	} with { variant (len) "LENGTHTO(alg_id,key)" };
 
-	template RSL_IE_EncryptionInfo tr_RSL_IE_EncrInfo(template OCT1 alg, template octetstring key) := {
+	template RSL_IE_EncryptionInfo tr_RSL_IE_EncrInfo(template RSL_AlgId alg,
+							  template octetstring key) := {
 		len := ?,
 		alg_id := alg,
 		key := key
 	}
-	template (value) RSL_IE_EncryptionInfo ts_RSL_IE_EncrInfo(OCT1 alg, octetstring key) := {
+	template (value) RSL_IE_EncryptionInfo ts_RSL_IE_EncrInfo(template (value) RSL_AlgId alg,
+								  octetstring key) := {
 		len := 0, /* overwritten */
 		alg_id := alg,
 		key := key
@@ -1154,7 +1166,7 @@
 	/* 8.4.6 BSC ->BTS */
 	template RSL_Message tr_RSL_ENCR_CMD(template RslChannelNr chan_nr,
 					     template RslLinkId link_id := ?,
-					     template OCT1 alg := ?,
+					     template RSL_AlgId alg := ?,
 					     template octetstring key := ?,
 					     template octetstring l3_info := ?) := {
 		msg_disc := tr_RSL_MsgDisc(RSL_MDISC_DCHAN, false),
@@ -1168,7 +1180,7 @@
 	}
 	template (value) RSL_Message ts_RSL_ENCR_CMD(template (value) RslChannelNr chan_nr,
 						     template (value) RslLinkId link_id,
-						     OCT1 alg, octetstring key,
+						     template (value) RSL_AlgId alg, octetstring key,
 						     octetstring l3_info) := {
 		msg_disc := ts_RSL_MsgDisc(RSL_MDISC_DCHAN, false),
 		msg_type := RSL_MT_ENCR_CMD,