The present invention relates to a housing of a drug delivery device comprising a cylindrically shaped body (12) to accommodate a drive mechanism (13) and comprising a cartridge holder (14) to accommodate a cartridge (16) containing a dispensable medicament, the housing further comprising a connector assembly (20) to releasably interconnect body (12) and cartridge holder (14), the connector assembly (20) comprising: a tangentially extending recessed structure (30) with a tangential opening (31) to receive a radially extending pin (26), wherein the recessed structure (30) is fastened to one of body (12) and cartridge holder (14) and wherein the pin (26) is fastened to the other one of body (12) and cartridge holder (14), a release member (40) having a retaining portion (42) to cover the opening (31) in a locking configuration (60), wherein the release member (40) is displaceable in tangential direction (3) against a restoring force away from the recessed structure (30) into a release configuration (62), in which the opening (31) is uncovered to tangentially remove the pin (26) therefrom.
