A method of making a pneumatic tire, the method comprising the steps of: mixing a sealant composition comprising an elastomer, a diluent, a quinoid curing agent, an oxidant co-curative and a cure modifier of the formula wherein R 1 and R 2 are independently selected to be H or a C1 to C4 alkyl, or R 1 and R 2 taken together form a substituted or unsubstituted phenylene group, R 3 and R 4 are independently selected to be H, -OH -NH 2, a C1 to C4 alkyl, or -OR 5 where R 5 is a C1 to C4 alkyl, with the proviso that when R 1 and R 2 are taken together to form a substituted or unsubstituted phenylene group, R 5 is a C1 to C3 alkyl; applying the sealant composition to an inner surface of a cured tire (10, 10a); and curing the sealant composition; characterized in that the cure modifier is selected from the group consisting of phthalic acid, monoalkyl phthalates, dialkyl phthalates, phthalic acid monoamides, phthalic acid diamides, phthalaldehyde, o-diacetylbenzene, maleic acid, monoalkyl maleates, maleic acid monoamides, maleic acid diamides, citraconic acid, monoalkyl citraconate, dialkyl citraconates, citraconic acid monoamides, citraconic acid diamides, 2-butenedial-2Z, trimellitic acid, monoalkyl trimellitates, dialkyltrimellitates, trialkyltrimellitates, hemimellitic acid, monoalkyl hemimellitates, dialky hemimellitates, trialkyl hemimellitates, pyromellitic acid, monoalkyl pyromellitates, dialkyl pyromellitates, trialkyl pyromellitates, and tetraalkyl pyromellitates; and/or in that the sealant composition further comprises a cure retarder selected from ethylene glycol, alkyl-substituted ethylene glycols, ethylene diamine, and alkyl-substituted ethylene diamines. mixing a sealant composition comprising an elastomer, a diluent, a quinoid curing agent, an oxidant co-curative and a cure modifier of the formula wherein R 1 and R 2 are independently selected to be H or a C1 to C4 alkyl, or R 1 and R 2 taken together form a substituted or unsubstituted phenylene group, R 3 and R 4 are independently selected to be H, -OH -NH 2, a C1 to C4 alkyl, or -OR 5 where R 5 is a C1 to C4 alkyl, with the proviso that when R 1 and R 2 are taken together to form a substituted or unsubstituted phenylene group, R 5 is a C1 to C3 alkyl; applying the sealant composition to an inner surface of a cured tire (10, 10a); and curing the sealant composition; characterized in that the cure modifier is selected from the group consisting of phthalic acid, monoalkyl phthalates, dialkyl phthalates, phthalic acid monoamides, phthalic acid diamides, phthalaldehyde, o-diacetylbenzene, maleic acid, monoalkyl maleates, maleic acid monoamides, maleic acid diamides, citraconic acid, monoalkyl citraconate, dialkyl citraconates, citraconic acid monoamides, citraconic acid diamides, 2-butenedial-2Z, trimellitic acid, monoalkyl trimellitates, dialkyltrimellitates, trialkyltrimellitates, hemimellitic acid, monoalkyl hemimellitates, dialky hemimellitates, trialkyl hemimellitates, pyromellitic acid, monoalkyl pyromellitates, dialkyl pyromellitates, trialkyl pyromellitates, and tetraalkyl pyromellitates; and/or in that the sealant composition further comprises a cure retarder selected from ethylene glycol, alkyl-substituted ethylene glycols, ethylene diamine, and alkyl-substituted ethylene diamines.