diff --git a/openair3/NAS/NR_UE/nr_nas_msg_sim.c b/openair3/NAS/NR_UE/nr_nas_msg_sim.c
index c942e079cd..87953f8b4c 100644
--- a/openair3/NAS/NR_UE/nr_nas_msg_sim.c
+++ b/openair3/NAS/NR_UE/nr_nas_msg_sim.c
@@ -1449,9 +1449,13 @@ void *nas_nrue(void *args_p)
               offset++;
             }
           } break;
-          case FGS_PDU_SESSION_ESTABLISHMENT_REJ:
-            LOG_E(NAS, "Received PDU Session Establishment reject\n");
-            break;
+	case FGS_PDU_SESSION_ESTABLISHMENT_REJ:
+	  LOG_E(NAS, "Received PDU Session Establishment reject\n");
+	  break;
+	case REGISTRATION_REJECT:
+	  LOG_E(NAS, "Received Registration reject\n");
+	  exit(1);
+	  break;
           default:
             LOG_W(NR_RRC, "unknown message type %d\n", msg_type);
             break;
diff --git a/openair3/NAS/NR_UE/nr_nas_msg_sim.h b/openair3/NAS/NR_UE/nr_nas_msg_sim.h
index c52096107d..bb54660bbd 100644
--- a/openair3/NAS/NR_UE/nr_nas_msg_sim.h
+++ b/openair3/NAS/NR_UE/nr_nas_msg_sim.h
@@ -52,6 +52,7 @@
 #define REGISTRATION_REQUEST                               0b01000001 /* 65 = 0x41 */
 #define REGISTRATION_ACCEPT                                0b01000010 /* 66 = 0x42 */
 #define REGISTRATION_COMPLETE                              0b01000011 /* 67 = 0x43 */
+#define REGISTRATION_REJECT                                68
 #define FGS_DEREGISTRATION_REQUEST_UE_ORIGINATING          0b01000101
 #define FGS_DEREGISTRATION_ACCEPT                          0b01000110
 #define FGS_AUTHENTICATION_REQUEST                         0b01010110 /* 86 = 0x56 */