Hello list, I found an interference between the "frac" opentype feature and \setbreakpoints[compound], which make the former fail when you have a numerator more than 2 digit wide. I found it with Adobe Garamond Premier Pro: with \setbreakpoints[compound], when the fraction had a 3-digit (or more) numerator, the denominator stayed high as the numerator (like a superscript). Here I replaced Garamond Premier Pro with the freely available "Lato" font, to let you reproduce the problem. The outcome is different, but still erroneous: \setbreakpoints[compound] makes ConTeXt ignore the "frac" feature at all. Please try this: \definefontfeature[frac][frac=yes] \definefontfamily[default][rm][lato][features=frac] \setupbodyfont[default,rm,11pt] \setbreakpoints[compound] \starttext \addff{frac} 1/3, 1/100, 1/1000, {\setbreakpoints[reset]1633/100}, 2345/12. \stoptext A workaround is a local \setbreakpoints[reset] limited to the fraction. Best regards, Massi