diff --git a/library/GSUP_Types.ttcn b/library/GSUP_Types.ttcn
index 6cc6dde..c024d37 100644
--- a/library/GSUP_Types.ttcn
+++ b/library/GSUP_Types.ttcn
@@ -52,7 +52,10 @@
 	OSMO_GSUP_SM_RP_UI_IE		('43'O),
 	OSMO_GSUP_SM_RP_CAUSE_IE	('44'O),
 	OSMO_GSUP_SM_RP_MMS_IE		('45'O),
-	OSMO_GSUP_SM_ALERT_RSN_IE	('46'O)
+	OSMO_GSUP_SM_ALERT_RSN_IE	('46'O),
+
+	OSMO_GSUP_IMEI_IE		('50'O),
+	OSMO_GSUP_IMEI_RESULT_IE	('51'O)
 } with { variant "FIELDLENGTH(8)" };
 
 type enumerated GSUP_MessageType {
@@ -96,7 +99,11 @@
 
 	OSMO_GSUP_MSGT_READY_FOR_SM_REQUEST	('00101100'B),
 	OSMO_GSUP_MSGT_READY_FOR_SM_ERROR	('00101101'B),
-	OSMO_GSUP_MSGT_READY_FOR_SM_RESULT	('00101110'B)
+	OSMO_GSUP_MSGT_READY_FOR_SM_RESULT	('00101110'B),
+
+	OSMO_GSUP_MSGT_CHECK_IMEI_REQUEST	('00110000'B),
+	OSMO_GSUP_MSGT_CHECK_IMEI_ERROR		('00110001'B),
+	OSMO_GSUP_MSGT_CHECK_IMEI_RESULT	('00110010'B)
 } with { variant "FIELDLENGTH(8)" };
 
 type enumerated GSUP_CancelType {
@@ -109,6 +116,11 @@
 	OSMO_GSUP_CN_DOMAIN_CS			(2)
 } with { variant "FIELDLENGTH(8)" };
 
+type enumerated GSUP_IMEIResult {
+	OSMO_GSUP_IMEI_RESULT_ACK		(0),
+	OSMO_GSUP_IMEI_RESULT_NACK		(1)
+} with { variant "FIELDLENGTH(8)" };
+
 type enumerated GSUP_SessionState {
 	OSMO_GSUP_SESSION_STATE_NONE		(0),
 	OSMO_GSUP_SESSION_STATE_BEGIN		(1),
@@ -121,6 +133,11 @@
 	hexstring digits optional
 } with { variant (len) "LENGTHTO(digits)" };
 
+type record GSUP_IMEI {
+	uint8_t	len,
+	hexstring digits optional
+} with { variant (len) "LENGTHTO(digits)" };
+
 type record GSUP_IE {
 	GSUP_IEI	tag,
 	uint8_t		len,
@@ -156,6 +173,8 @@
 				 sm_rp_cause, tag = OSMO_GSUP_SM_RP_CAUSE_IE;
 				 sm_rp_mms, tag = OSMO_GSUP_SM_RP_MMS_IE;
 				 sm_alert_rsn, tag = OSMO_GSUP_SM_ALERT_RSN_IE;
+				 imei, tag = OSMO_GSUP_IMEI_IE;
+				 imei_result, tag = OSMO_GSUP_IMEI_RESULT_IE;
 			)"
 };
 
@@ -197,7 +216,10 @@
 	octetstring		sm_rp_ui,
 	OCT1			sm_rp_cause,
 	OCT1			sm_rp_mms,
-	GSUP_SM_ALERT_RSN_Type	sm_alert_rsn
+	GSUP_SM_ALERT_RSN_Type	sm_alert_rsn,
+
+	GSUP_IMEI		imei,
+	GSUP_IMEIResult		imei_result
 };
 
 type record GSUP_PDU {
@@ -674,6 +696,36 @@
 	}
 }
 
+template (value) GSUP_IE ts_GSUP_IE_IMEI_IE(GSUP_IMEI imei) := {
+	tag := OSMO_GSUP_IMEI_IE,
+	len := 0, /* overwritten */
+	val := {
+		imei := imei
+	}
+}
+template GSUP_IE tr_GSUP_IE_IMEI_IE(template GSUP_IMEI imei) := {
+	tag := OSMO_GSUP_IMEI_IE,
+	len := ?,
+	val := {
+		imei := imei
+	}
+}
+
+template (value) GSUP_IE ts_GSUP_IE_IMEI_RESULT_IE(GSUP_IMEIResult result) := {
+	tag := OSMO_GSUP_IMEI_RESULT_IE,
+	len := 0, /* overwritten */
+	val := {
+		imei_result := result
+	}
+}
+template GSUP_IE tr_GSUP_IE_IMEI_RESULT_IE(template GSUP_IMEIResult result) := {
+	tag := OSMO_GSUP_IMEI_RESULT_IE,
+	len := ?,
+	val := {
+		imei_result := result
+	}
+}
+
 /* Possible identity types for SM-RP-{OA|DA} IEs */
 type enumerated GSUP_SM_RP_ODA_IdType {
 	OSMO_GSUP_SM_RP_ODA_ID_NONE		('00'O),