The dependence of two-particle Bose-Einstein correlations on the squared invariant momentum difference Q2 has been calculated in models with fixed space-time sizes of the pion source. The resulting correlation functions have a sharp and approximately power-like peak at small Q in agreement with recent data of the UA1 Collaboration. The kinematical origin of the small Q peak is established thus showing that the observed Q-dependence does not necessarily imply evidence for intermittency.