diff --git a/unittest/libmariadb/t_conc173.c b/unittest/libmariadb/t_conc173.c
index 24c64e20..5b9369b1 100644
--- a/unittest/libmariadb/t_conc173.c
+++ b/unittest/libmariadb/t_conc173.c
@@ -31,8 +31,9 @@ static int test_conc_173(MYSQL *unused __attribute__((unused)))
 {
   MYSQL mysql;
   int arg;
+  int i;
 
-  for (int i = 0; i < 1000; i++)
+  for (i = 0; i < 1000; i++)
   {
     mysql_init(&mysql);
     mysql_options(&mysql, MYSQL_READ_DEFAULT_GROUP, "client");