option 'innodb-log-buffer-size' adjusted

When setting innodb_log_buffer_size to more than 2gb, I get a warning in the logs:
[Warning] option 'innodb-log-buffer-size': unsigned value 3221225472 adjusted to 2147479552
[Warning] option 'innodb-log-buffer-size': unsigned value 2147483648 adjusted to 2147479552

The documentation for the variable specifies a maximum value of 4GB
https://mariadb.com/kb/en/innodb-system-variables/#innodb_log_buffer_size
Range: 262144 to 4294967295 (256KB to 4096MB)

Is there a rationale for this change in the variable?