This article deals with the distribution of the Von Neumann ratio of least-squares estimated regression disturbances. This distribution is approximated by a beta distribution under the condition that the behaviour of explanatory variables of the regression over time is sufficiently smooth. Two examples are presented, together with a table containing 1 and 5 per cent significance limits for a number of observations ranging from 15 to 100 and a number of coefficients adjusted ranging from 2 to 6.