Put your collaborator’s name on it. Stealing credit is the fastest way to work alone forever.

Credit is cheap to give and expensive to take. Naming the person who helped costs you nothing real, since nobody thinks less of you for having collaborators, and everybody notices when a name goes missing. The people who quietly get left off remember with startling accuracy. Word travels, and then the interesting projects stop including you.

When you post the thing or hand it in, say who did what, specifically. Not a vague thanks at the end, the actual contribution. Do it even when they will never see it, because that is where the habit actually gets set.