array_merge()

When I use the forms module via the survey module, each time I add a field, I get several messages of the following sort:

warning: array_merge() [function.array-merge]: Argument #2 is not an array in /var/wallace/modules/forms/forms.module on line 41.

I fixed it by changing:
$return = array_merge($return, $result);
to $return = array_merge($return, (array)$result);
but I have no idea if that's the right way to do it. It seems to work, though. Forms submit and results are stored.