Plotly, ggplot R modify legends

I have a ggplot graphic that I’d like to make interactive by passing it to ggplotly. When I do, plotly discards the ggplot legend and creates its own. With ggplot, I get a legend for each dimension (plotting character, color, etc.)

The ggplotly function produces what I think of as a “Cartesian Product Legend”. That is, there is one legend with a line for each color and shape combination. I’ve been Googling for the past day looking for a way to customize the legend, but with nothing helpful, I find myself here.

What am I missing?