diff --git a/unittest/libmariadb/misc.c b/unittest/libmariadb/misc.c
index af97f509..b0e53f5c 100644
--- a/unittest/libmariadb/misc.c
+++ b/unittest/libmariadb/misc.c
@@ -235,7 +235,7 @@ static int test_frm_bug(MYSQL *mysql)
   MYSQL_ROW  row;
   FILE       *test_file;
   char       data_dir[FN_REFLEN];
-  char       test_frm[FN_REFLEN];
+  char       test_frm[1024];
   int        rc;
 
   mysql_autocommit(mysql, TRUE);
@@ -269,7 +269,7 @@ static int test_frm_bug(MYSQL *mysql)
   rc= mysql_stmt_fetch(stmt);
   FAIL_UNLESS(rc == MYSQL_NO_DATA, "rc != MYSQL_NO_DATA");
 
-  sprintf(test_frm, "%s/%s/test_frm_bug.frm", data_dir, schema);
+  snprintf(test_frm, 1024, "%s/%s/test_frm_bug.frm", data_dir, schema);
 
 
   if (!(test_file= fopen(test_frm, "w")))