diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c
index 02f217ced5..4e404a4e80 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c
@@ -389,8 +389,8 @@ void nr_schedule_uss_dlsch_phytest(module_id_t   module_idP,
       //Sending SDUs with size 1
       //Initialize elements of sdu_lcids and sdu_lengths
       sdu_lcids[0] = 0x05; // DRB
-      sdu_lengths[0] = TBS_bytes-3;
-      header_length_total += 2;
+      sdu_lengths[0] = TBS_bytes - ta_len - 3;
+      header_length_total += 2 + (sdu_lengths[0] >= 128);
       sdu_length_total += sdu_lengths[0];
       num_sdus +=1;
     } // else IS_SOFTMODEM_NOS1