diff --git a/gap/digraph.gi b/gap/digraph.gi
index 8f17bc8fd..d7a2169f2 100644
--- a/gap/digraph.gi
+++ b/gap/digraph.gi
@@ -1314,11 +1314,11 @@ function(filt, digraph, gps, homs)
     fi;
   od;
 
-  reps := [];
+  reps := EmptyPlist(n);
   for i in [1 .. n] do
     rep := IsomorphismPermGroup(gps[i]);
     rep := rep * SmallerDegreePermutationRepresentation(Image(rep));
-    Add(reps, rep);
+    reps[i] := rep;
   od;
 
   top     := DigraphTopologicalSort(digraph);
diff --git a/tst/standard/digraph.tst b/tst/standard/digraph.tst
index 25f8dcc53..4c458f29e 100644
--- a/tst/standard/digraph.tst
+++ b/tst/standard/digraph.tst
@@ -13,11 +13,11 @@
 #@local adjacencies, b, bin, c, c1, c2, d, di, digraph, divides, elms, eq
 #@local eq_distr, eq_new, error, f, failed, failed_names, failed_values, foo, g
 #@local gr, gr1, gr2, gr3, gr4, gr5, graph, graph1, graph2, grnc, group, h
-#@local hom13, hom21, hom23, hom31, hom41, hom42, hom52, hom53, i, im, inn
-#@local isGraph, iso, iso_distr, iso_new, j, k, list, m, main, mat, n, name
+#@local hom13, hom21, hom23, hom31, hom41, hom42, hom52, hom53, i, idhom, im
+#@local inn, isGraph, iso, iso_distr, iso_new, j, k, list, m, main, mat, n, name
 #@local name2, names, new, order, p, prop, properties, r, r1, r2, record, rel1
-#@local rel2, rel3, representatives, s, schreierVector, sgn, temp, test, v, x
-#@local xxx, y
+#@local rel2, rel3, representatives, s, schreierVector, sgn, swaphom, temp
+#@local test, v, x, xxx, y
 gap> START_TEST("Digraphs package: standard/digraph.tst");
 gap> LoadPackage("digraphs", false);;
 
@@ -1515,6 +1515,9 @@ Error, no 2nd choice method found for `AsSemigroup' on 2 arguments
 gap> S := AsMonoid(IsTransformation, di);;
 Error, the 1st argument <filt> must be IsPartialPermMonoid or IsPartialPermSem\
 igroup,
+gap> AsSemigroup(IsTransformationSemigroup, ChainDigraph(3), [], []);
+Error, no method found! For debugging hints type ?Recovery from NoMethodFound
+Error, no 2nd choice method found for `AsSemigroup' on 4 arguments
 
 # AsSemigroup (for IsPartialPermSemigroup, a digraph, a list of groups,
 # and homomorphisms)
@@ -1578,6 +1581,9 @@ gap> Size(T);
 24
 gap> Size(GreensHClassOfElement(T, Representative(T)));
 24
+gap> T := AsSemigroup(IsPartialPermSemigroup, gr3, [Group(())], []);;
+gap> Size(T);
+1
 gap> gr4 := Digraph([[1], [1, 2], [1, 3], [1, 4], [1, 2, 3, 5]]);;
 gap> G5 := AlternatingGroup(4);;
 gap> G2 := SymmetricGroup(4);;
@@ -1671,6 +1677,18 @@ gap> T := AsSemigroup(IsPartialPermSemigroup, gr4, [G1, G2, G3, G4, G5],
 > [[2, 1, hom21], [3, 1, hom31], [4, 1, hom41], [5, 2, hom52], [5, 2, hom52]]);;
 Error, the fourth argument must contain a triple [i, j, hom] for each edge [i,\
  j] in the reflexive transitive reduction of the second argument,
+gap> D := Digraph([[1, 2, 3, 4], [2, 4], [3, 4], [4]]);;
+gap> OutNeighbours(DigraphReflexiveTransitiveReduction(D));
+[ [ 2, 3 ], [ 4 ], [ 4 ], [  ] ]
+gap> G := SymmetricGroup(4);;
+gap> idhom := GroupHomomorphismByFunction(G, G, IdFunc);;
+gap> swaphom := GroupHomomorphismByFunction(G, G, x -> x ^ (1, 2));;
+gap> T := AsSemigroup(IsPartialPermSemigroup, D, [G, G, G, G],
+> [[1, 2, idhom], [1, 3, swaphom], [2, 4, idhom], [3, 4, swaphom]]);
+<partial perm semigroup of rank 16 with 8 generators>
+gap> T := AsSemigroup(IsPartialPermSemigroup, D, [G, G, G, G],
+> [[1, 2, idhom], [1, 3, swaphom], [2, 4, idhom], [3, 4, idhom]]);
+Error, the homomorphisms given must form a commutative diagram,
 
 # MakeImmutable
 gap> D := NullDigraph(IsMutableDigraph, 10);