diff --git a/openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c b/openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c
index f40d822b6b..ef31357a1f 100644
--- a/openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c
+++ b/openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c
@@ -1615,92 +1615,156 @@ uint16_t Table_61412[28][2] = {{2,30},{2,40},{2,50},{2,64},{2,78},{2,99},{2,120}
 uint8_t nr_get_Qm_dl(uint8_t Imcs, uint8_t table_idx) {
   switch(table_idx) {
     case 0:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 0 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51311[Imcs][0]);
     break;
 
     case 1:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 1 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_51312[Imcs][0]);
     break;
 
     case 2:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 2 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51313[Imcs][0]);
     break;
 
     default:
-      AssertFatal(0, "Invalid MCS table index %d (expected in range [1,3])\n", table_idx);
+      AssertFatal(0, "Invalid MCS table index %d (expected in range [0,2])\n", table_idx);
   }
 }
 
 uint32_t nr_get_code_rate_dl(uint8_t Imcs, uint8_t table_idx) {
   switch(table_idx) {
     case 0:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 0 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51311[Imcs][1]);
     break;
 
     case 1:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 1 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_51312[Imcs][1]);
     break;
 
     case 2:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 2 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51313[Imcs][1]);
     break;
 
     default:
-      AssertFatal(0, "Invalid MCS table index %d (expected in range [1,3])\n", table_idx);
+      AssertFatal(0, "Invalid MCS table index %d (expected in range [0,2])\n", table_idx);
   }
 }
 
 uint8_t nr_get_Qm_ul(uint8_t Imcs, uint8_t table_idx) {
   switch(table_idx) {
     case 0:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 0 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51311[Imcs][0]);
     break;
 
     case 1:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 1 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_51312[Imcs][0]);
     break;
 
     case 2:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 2 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51313[Imcs][0]);
     break;
 
     case 3:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 3 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_61411[Imcs][0]);
     break;
 
     case 4:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 4 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_61412[Imcs][0]);
     break;
 
     default:
-      AssertFatal(0, "Invalid MCS table index %d (expected in range [1,2])\n", table_idx);
+      AssertFatal(0, "Invalid MCS table index %d (expected in range [0,4])\n", table_idx);
   }
 }
 
 uint32_t nr_get_code_rate_ul(uint8_t Imcs, uint8_t table_idx) {
   switch(table_idx) {
     case 0:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 0 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51311[Imcs][1]);
     break;
 
     case 1:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 1 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_51312[Imcs][1]);
     break;
 
     case 2:
+      if (Imcs > 28) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 2 (expected range [0,28])\n", Imcs);
+        Imcs = 28;
+      }
       return (Table_51313[Imcs][1]);
     break;
 
     case 3:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 3 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_61411[Imcs][1]);
     break;
 
     case 4:
+      if (Imcs > 27) {
+        LOG_E(MAC, "Invalid MCS index %d for MCS table 4 (expected range [0,27])\n", Imcs);
+        Imcs = 27;
+      }
       return (Table_61412[Imcs][1]);
     break;
 
     default:
-      AssertFatal(0, "Invalid MCS table index %d (expected in range [1,2])\n", table_idx);
+      AssertFatal(0, "Invalid MCS table index %d (expected in range [0,4])\n", table_idx);
   }
 }
 
diff --git a/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c b/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
index c4ee06cd2f..8f83ef8676 100644
--- a/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
+++ b/openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
@@ -3802,7 +3802,8 @@ void nr_ue_process_mac_pdu(module_id_t module_idP,
         }
         pdu_ptr += ( mac_subheader_len + mac_ce_len + mac_sdu_len );
         pdu_len -= ( mac_subheader_len + mac_ce_len + mac_sdu_len );
-        AssertFatal(pdu_len >= 0, "[MAC] nr_ue_process_mac_pdu, residual mac pdu length < 0!\n");
+        if (pdu_len < 0)
+          LOG_E(MAC, "[MAC] nr_ue_process_mac_pdu, residual mac pdu length %d < 0!\n", pdu_len);
     }
 }