diff --git a/include/mariadb_stmt.h b/include/mariadb_stmt.h
index 1947c83d..347eaf2c 100644
--- a/include/mariadb_stmt.h
+++ b/include/mariadb_stmt.h
@@ -38,7 +38,9 @@
 { \
   (a)->last_errno= (b);\
   strncpy((a)->sqlstate, (c), SQLSTATE_LENGTH);\
+  (a)->sqlstate[SQLSTATE_LENGTH]= 0;\
   strncpy((a)->last_error, (d) ? (d) : ER((b)), MYSQL_ERRMSG_SIZE - 1);\
+  (a)->last_error[MYSQL_ERRMSG_SIZE - 1]= 0;\
 }
 
 #define CLEAR_CLIENT_STMT_ERROR(a) \
diff --git a/include/mysql.h b/include/mysql.h
index ef41db5f..843489e1 100644
--- a/include/mysql.h
+++ b/include/mysql.h
@@ -125,7 +125,9 @@ extern unsigned int mariadb_deinitialize_ssl;
   { \
     (a)->net.last_errno= (b);\
     strncpy((a)->net.sqlstate, (c), SQLSTATE_LENGTH);\
+    (a)->net.sqlstate[SQLSTATE_LENGTH]= 0;\
     strncpy((a)->net.last_error, (d) ? (d) : ER((b)), MYSQL_ERRMSG_SIZE - 1);\
+    (a)->net.last_error[MYSQL_ERRMSG_SIZE - 1]= 0;\
   }
 
 /* For mysql_async.c */