diff --git a/src/sysmo_l1_if.c b/src/sysmo_l1_if.c
index a3a59c9..b03fad0 100644
--- a/src/sysmo_l1_if.c
+++ b/src/sysmo_l1_if.c
@@ -170,8 +170,8 @@
 
 	gsmtap_send(fl1h->gsmtap, data_ind->u16Arfcn | GSMTAP_ARFCN_F_UPLINK,
 			data_ind->u8Tn, GSMTAP_CHANNEL_PACCH, 0,
-			data_ind->u32Fn, 0, 0, data_ind->msgUnitParam.u8Buffer,
-			data_ind->msgUnitParam.u8Size);
+			data_ind->u32Fn, 0, 0, data_ind->msgUnitParam.u8Buffer+1,
+			data_ind->msgUnitParam.u8Size-1);
 
 	DEBUGP(DL1IF, "Rx PH-DATA.ind %s (hL2 %08x): %s",
 		get_value_string(femtobts_l1sapi_names, data_ind->sapi),