In Borceux's Handbook of Categorical Algebra Volume 1, exercise 8.4.2 defines an internal distributor in a category $\mathcal{C}$ with finite limits and coequalizers as an internal base-valued functor $\bf{\mathcal{B}^{op}}\times\bf{\mathcal{A}}\rightarrow \mathcal{C}$ and asks you to define the composite of two such internal distributors.
In Johnstone's Sketches of an Elephant, internal profunctors are defined similarly in section B2.7, with the only difference being that he assumes that our base category $\mathcal{C}$ has internal products, coequalizers of reflexive pairs, and that those are stable under pullback (i.e., they are universal). This assumption is used explicitly in the construction.
My question then is, is it possible to compose internal distributors under Borceux's conditions and I'm just not seeing it or is this a mistake?