LINCOLN, Neb. (AP) — A federal judge says an error he made during a synthetic marijuana case in Lincoln doesn’t justify a new trial.

U.S. District Judge Richard Kopf blamed himself Wednesday for a mistake made in the case of Allen Peithman, who faced a 14-count criminal complaint that alleged he sold synthetic marijuana at his head shop.

The complaint included allegations that Peithman violated his supervised release in an earlier drug case by participating in the alleged synthetic marijuana conspiracy.

Kopf said he mistakenly treated the supervised-release violation as a separate offense, rather than a sentencing enhancement, before Peithman was found guilty of six counts in March.

Kopf vacated the supervised-released ruling last month, but says it doesn’t warrant a new trial.

Peithman’s sentencing is set for June.