diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index f4fd6658171..599694b01ef 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -4299,6 +4299,8 @@ static int init_common_variables()
   if (IS_SYSVAR_AUTOSIZE(&server_version_ptr))
     set_server_version(server_version, sizeof(server_version));
 
+  mysql_real_data_home_len= strlen(mysql_real_data_home);
+
   if (!opt_abort)
   {
     if (IS_SYSVAR_AUTOSIZE(&server_version_ptr))