The present invention relates to a process for restabilizing free-radically polymerizable monomers. The process comprises the steps: (a) introduction of a solution of an inhibitor of the free-radical polymerization by means of an inert pressurized gas into a vessel (1) comprising the monomers via a line (10) which comprises an ascending region, and (b) mixing of the contents of the vessel and the inhibitor solution by blowing gas through the line (10). In step (a), the flow velocity of the pressurized gas is set so that plug flow or annular flow is obtained as flow regime of the inhibitor solution and in step (b) the superficial gas velocity is set to ≥0.1 mm/s. The present invention further relates to a supply unit (11) for carrying out the process.