diff --git a/openair2/LAYER2/NR_MAC_gNB/main.c b/openair2/LAYER2/NR_MAC_gNB/main.c
index ec8fe2010d..705bca639a 100644
--- a/openair2/LAYER2/NR_MAC_gNB/main.c
+++ b/openair2/LAYER2/NR_MAC_gNB/main.c
@@ -118,6 +118,19 @@ void clear_mac_stats(gNB_MAC_INST *gNB) {
   }
 }
 
+static char *st_append(char *start, const char *end, const char *format, ...)
+{
+  size_t space = end - start;
+  va_list args;
+  va_start(args, format);
+  size_t written = vsnprintf(start, space, format, args);
+  va_end(args);
+  if (written <= space)
+    return start + written;
+  else
+    return (char *)end;
+}
+
 size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset_rsrp)
 {
   const char *begin = output;
@@ -133,39 +146,39 @@ size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset
     const int avg_rsrp = stats->num_rsrp_meas > 0 ? stats->cumul_rsrp / stats->num_rsrp_meas : 0;
     const int avg_sinrx10 = stats->num_sinr_meas > 0 ? stats->cumul_sinrx10 / stats->num_sinr_meas : 0;
 
-    output += snprintf(output, end - output, "UE RNTI %04x CU-UE-ID ", UE->rnti);
+    output = st_append(output, end, "UE RNTI %04x CU-UE-ID ", UE->rnti);
     if (du_exists_f1_ue_data(UE->rnti)) {
       f1_ue_data_t ued = du_get_f1_ue_data(UE->rnti);
-      output += snprintf(output, end - output, "%d", ued.secondary_ue);
+      output = st_append(output, end, "%d", ued.secondary_ue);
     } else {
-      output += snprintf(output, end - output, "(none)");
+      output = st_append(output, end, "(none)");
     }
 
     bool in_sync = !sched_ctrl->ul_failure;
-    output += snprintf(output,
-                       end - output,
+    output = st_append(output,
+                       end,
                        " %s PH %d dB PCMAX %d dBm",
                        in_sync ? "in-sync" : "out-of-sync",
                        sched_ctrl->ph,
                        sched_ctrl->pcmax);
 
     if (stats->num_rsrp_meas)
-      output += snprintf(output, end - output, ", average RSRP %d (%d meas)", avg_rsrp, stats->num_rsrp_meas);
+      output = st_append(output, end, ", average RSRP %d (%d meas)", avg_rsrp, stats->num_rsrp_meas);
 
     if (stats->num_sinr_meas) {
-      output += snprintf(output,
-                         end - output,
+      output = st_append(output,
+                         end,
                          ", average SINR %d.%d (%d meas)",
                          avg_sinrx10 / 10,
                          avg_sinrx10 % 10,
                          stats->num_sinr_meas);
     }
 
-    output += snprintf(output, end - output, "\n");
+    output = st_append(output, end, "\n");
 
     if(sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.print_report)
-      output += snprintf(output,
-                         end - output,
+      output = st_append(output,
+                         end,
                          "UE %04x: CQI %d, RI %d, PMI (%d,%d)\n",
                          UE->rnti,
                          sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.wb_cqi_1tb,
@@ -174,18 +187,18 @@ size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset
                          sched_ctrl->CSI_report.cri_ri_li_pmi_cqi_report.pmi_x2);
 
     if (stats->srs_stats[0] != '\0') {
-      output += snprintf(output, end - output, "UE %04x: %s\n", UE->rnti, stats->srs_stats);
+      output = st_append(output, end, "UE %04x: %s\n", UE->rnti, stats->srs_stats);
     }
 
-    output += snprintf(output,
-                       end - output,
+    output = st_append(output,
+                       end,
                        "UE %04x: dlsch_rounds ", UE->rnti);
-    output += snprintf(output, end - output, "%"PRIu64, stats->dl.rounds[0]);
+    output = st_append(output, end, "%"PRIu64, stats->dl.rounds[0]);
     for (int i = 1; i < gNB->dl_bler.harq_round_max; i++)
-      output += snprintf(output, end - output, "/%"PRIu64, stats->dl.rounds[i]);
+      output = st_append(output, end, "/%"PRIu64, stats->dl.rounds[i]);
 
-    output += snprintf(output,
-                       end - output,
+    output = st_append(output,
+                       end,
                        ", dlsch_errors %"PRIu64", pucch0_DTX %d, BLER %.5f MCS (%d) %d CCE fail %d\n",
                        stats->dl.errors,
                        stats->pucch0_DTX,
@@ -199,15 +212,15 @@ size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset
       stats->num_sinr_meas = 0;
       stats->cumul_sinrx10 = 0;
     }
-    output += snprintf(output,
-                       end - output,
+    output = st_append(output,
+                       end,
                        "UE %04x: ulsch_rounds ", UE->rnti);
-    output += snprintf(output, end - output, "%"PRIu64, stats->ul.rounds[0]);
+    output = st_append(output, end, "%"PRIu64, stats->ul.rounds[0]);
     for (int i = 1; i < gNB->ul_bler.harq_round_max; i++)
-      output += snprintf(output, end - output, "/%"PRIu64, stats->ul.rounds[i]);
+      output = st_append(output, end, "/%"PRIu64, stats->ul.rounds[i]);
 
-    output += snprintf(output,
-                       end - output,
+    output = st_append(output,
+                       end,
                        ", ulsch_errors %"PRIu64", ulsch_DTX %d, BLER %.5f MCS (%d) %d (Qm %d deltaMCS %d dB) NPRB %d  SNR %d.%d dB CCE fail %d\n",
                        stats->ul.errors,
                        stats->ulsch_DTX,
@@ -220,15 +233,15 @@ size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset
                        sched_ctrl->pusch_snrx10 / 10,
                        sched_ctrl->pusch_snrx10 % 10,
                        sched_ctrl->ul_cce_fail);
-    output += snprintf(output,
-                       end - output,
+   output = st_append(output,
+                       end,
                        "UE %04x: MAC:    TX %14"PRIu64" RX %14"PRIu64" bytes\n",
                        UE->rnti, stats->dl.total_bytes, stats->ul.total_bytes);
 
     for (int i = 0; i < seq_arr_size(&sched_ctrl->lc_config); i++) {
       const nr_lc_config_t *c = seq_arr_at(&sched_ctrl->lc_config, i);
-      output += snprintf(output,
-                         end - output,
+      output = st_append(output,
+                         end,
                          "UE %04x: LCID %d: TX %14"PRIu64" RX %14"PRIu64" bytes\n",
                          UE->rnti,
                          c->lcid,
@@ -236,6 +249,7 @@ size_t dump_mac_stats(gNB_MAC_INST *gNB, char *output, size_t strlen, bool reset
                          stats->ul.lc_bytes[c->lcid]);
     }
   }
+  DevAssert(output <= end);
   return output - begin;
 }