diff --git a/openair3/NAS/UE/API/USER/user_api.c b/openair3/NAS/UE/API/USER/user_api.c
index b3bd976b710c3d827cc4b4f773d28a55c99a27c3..4d47a4c2b322d5a7af8164c4fce4bd1e951ea545 100644
--- a/openair3/NAS/UE/API/USER/user_api.c
+++ b/openair3/NAS/UE/API/USER/user_api.c
@@ -276,7 +276,7 @@ int user_api_set_data(user_api_id_t *user_api_id, char *message)
 
   memset(user_api_id->recv_buffer, 0, USER_API_RECV_BUFFER_SIZE);
 
-  strncpy(user_api_id->recv_buffer, message, USER_API_RECV_BUFFER_SIZE);
+  strncpy(user_api_id->recv_buffer, message, USER_API_RECV_BUFFER_SIZE - 1);
   rbytes = strlen(user_api_id->recv_buffer);
 
   LOG_TRACE(INFO, "USR-API   - %d bytes write", rbytes);