A tamper-evident closure assembly (100) includes a connector (104) having a receptacle (108) defined by an outer surface of the connector, the receptacle having a depression (116) and a wall (112) adjacent the depression; a cap (130) configured to attach to the connector and to rotate around the connector; a locking mechanism (150) disposed on the cap, the locking mechanism having a locked configuration and an unlocked configuration, the locking mechanism having a tab (154) movable between the locked configuration and the unlocked configuration; and a plug (158) disposed on the tab, wherein when the locking mechanism is in the unlocked configuration, the plug is disposed outside of the receptacle on the connector, and when the locking mechanism is in the locked configuration, the plug is disposed at least partly within the receptacle, such that the cap is prevented from rotating around the connector.