Heed the warning of your co-worker’s “Don’t talk to me until I’ve had my coffee” mug.

Drinking coffee before having a conversation with someone helps you focus and feel better about the person you’re talking to, according to a new study.

“We see coffee being served in many meetings but found very little research on how coffee might affect group dynamics,” Vasa Unnava, an author on the study, told psypost.org. “Most research is about how coffee affects an individual.”

Researchers conducted an experiment with 134 coffee-drinking college students divided into two groups discussing Occupy Wall Street for 15 minutes. Participants who had a pre-discussion cup of coffee reported having an easier time focusing on their peers. The results were published in the Journal of Psychopharmacology.