fix someone's wagon

fix someone's wagon

Get even with someone, get revenge on someone, spoil someone's chance of success. For example, He may think he can win the election, but these ads will fix his wagon, or After what he did to her, her family's out to fix his wagon. This term uses fix in the sense of "punish someone" or "put someone in an awkward position," a usage dating from about 1800. The wagon was added in the 1900s, presumably making the phrase refer to putting sand in a wagon axle or similar sabotage.
See also: fix, wagon