Graph Theory - How can I solve a max flow problem in a mixed graph?

I am attempting to use graphmaxflow to find the max flow in a graph with directed and undirected edges.

To represent an undirected edge, I am splitting it into two edges one from i to j and one from j to i. I believe this is called a reciprocal edge.

Whenever I try to solve the problem I get the following error:

Error using graphalgs
Reciprocal edges are not allowed in
maxflow algorithms.

Error in graphmaxflow (line 97)
        [m,flow] =
        graphalgs(algorithmkeys{algorithm},debug_level,true,G,S,D);

Error in di_test (line 8)
[Mf,Fm,Ct] = graphmaxflow(Y,1,3,'Method',
'Edmonds')

Is there another algorithm or technique to solve max flow problems in mixed graphs?