A coupling device couples a drive shaft of a pivot drive (30) of an exhaust gas stream exhaust flap (10) for an internal combustion engine with a pivot shaft (14), which is rotatable about a pivot axis (A) and carries a flap member (16). The coupling device includes a coupling element (46) with a first coupling area (42) positive-locking engaging with a drive shaft (34) and with a second coupling area (44) positive-locking engaging with a pivot shaft. A prestressing element (58) is supported in relation to the coupling element and in relation to a support element (66) and prestresses the coupling element in a direction of a coupling axis (K), axially away from the support element and in a circumferential direction. A preassembly-blocking device (78) holds the support element under axial prestress and circumferential prestress in a preassembled position in relation to the coupling element.