diff --git a/openair2/COMMON/ngap_messages_types.h b/openair2/COMMON/ngap_messages_types.h
index a15c7df650..e66a7eab41 100644
--- a/openair2/COMMON/ngap_messages_types.h
+++ b/openair2/COMMON/ngap_messages_types.h
@@ -399,7 +399,7 @@ typedef struct ngap_register_gnb_req_s {
   char *gNB_name;
 
   /* Tracking area code */
-  uint16_t tac;
+  uint32_t tac;
 
 #define PLMN_LIST_MAX_SIZE 6
   /* Mobile Country Code
diff --git a/openair3/NGAP/ngap_gNB_defs.h b/openair3/NGAP/ngap_gNB_defs.h
index ee97f0fa9f..362f2cc5b3 100644
--- a/openair3/NGAP/ngap_gNB_defs.h
+++ b/openair3/NGAP/ngap_gNB_defs.h
@@ -248,7 +248,7 @@ typedef struct ngap_gNB_instance_s {
   enum cell_type_e cell_type;
 
   /* Tracking area code */
-  uint16_t tac;
+  uint32_t tac;
 
   /* gNB NGAP IP address */
   net_ip_address_t gNB_ng_ip;