diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index 73d2818..4398cea 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -1766,6 +1766,22 @@
 	}
 }
 
+template PDU_L3_SGSN_MS tr_GMM_DET_REQ_MT(template BIT3 dtt := ?, template boolean power_off := ?) := {
+	discriminator := '1000'B,
+	tiOrSkip := {
+		skipIndicator := '0000'B
+	},
+	msgs := {
+		gprs_mm := {
+			detachRequest_SGSN_MS := {
+				messageType := '00000101'B,
+				detachType := { dtt, bool2bit_tmpl(power_off) },
+				forceToStandby := ?,
+				gmmCause := *
+			}
+		}
+	}
+}
 
 function ts_ApnTLV(template (omit) octetstring apn) return template (omit) AccessPointNameTLV {
 	if (istemplatekind(apn, "omit")) {