Speakers often produce definite referring expressions that areoverspecified: they tend to include more attributes than neces-sary to distinguish the target referent. The current paper inves-tigates how the occurrence of overspecification is affected byviewing time. We conducted an experiment in which speakerswere asked to refer to target objects in visual domains. Half ofthe speakers had unlimited time to inspect the domains, whileviewing time was limited (1000 ms) for the other half. The re-sults reveal that limited viewing time induces the occurrenceof overspecification. We conjecture that limited viewing timecaused speakers to rely heavily on quick heuristics during at-tribute selection, which urge them to select attributes that areperceptually salient. In the case of unlimited inspection time,speakers seem to rely on a combination of heuristic and moredeliberate selection strategies.