Speakers often produce definite referring expressions that are overspecified: 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 by viewing time. We conducted an experiment in which speakers were asked to refer to target objects in visual domains. Half of the speakers had unlimited time to inspect the domains, while viewing time was limited (1000 ms) for the other half. The results reveal that limited viewing time induces the occurrence of overspecification. We conjecture that limited viewing time caused speakers to rely heavily on quick heuristics during attribute selection, which urge them to select attributes that are perceptually salient. In the case of unlimited inspection time, speakers seem to rely on a combination of heuristic and more deliberate selection strategies.