diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index c110baa9634..2a8e4b4c16b 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -9299,7 +9299,7 @@ static int test_if_case_insensitive(const char *dir_name)
                                buff, 0666, O_RDWR, MYF(0))) < 0)
   {
     if (!opt_abort)
-      sql_print_warning("Can't create test file %s", buff);
+      sql_print_warning("Can't create test file '%s' (Errcode: %M)", buff, my_errno);
     DBUG_RETURN(-1);
   }
   mysql_file_close(file, MYF(0));