diff --git a/library/RLCMAC_Templates.ttcn b/library/RLCMAC_Templates.ttcn
index 560074f..5ad1b4f 100644
--- a/library/RLCMAC_Templates.ttcn
+++ b/library/RLCMAC_Templates.ttcn
@@ -317,7 +317,7 @@
 		return 0;
 	}
 
-	template (value) RlcmacUlBlock ts_RLC_UL_CTRL_ACK(RlcmacUlCtrlMsg ctrl,
+	template (value) RlcmacUlBlock ts_RLC_UL_CTRL_ACK(template (value) RlcmacUlCtrlMsg ctrl,
 							MacPayloadType pt := MAC_PT_RLCMAC_NO_OPT,
 							boolean retry := false) := {
 		ctrl := {