Adjudication is often described as a "rough and ready" form of justice, where mistakes in decisions inevitably occur. Sometimes the mistake results from an adjudicator's mathematical error in his calculation of the sum to be paid. The orthodox view for many years has been that such an error cannot prevent the enforcement of the adjudicator's decision by the courts. This view is now under threat in the light of the recent judgment of Edwards-Stuart J in Geoffrey Osborne Ltd v Atkins Rail Ltd [2009] EWHC 2425 (TCC) (although heard in 2009 the judgment has only very recently become available). Our e-bulletin published on 17 February 2010 reports on this case.