import { ZodNullableDef } from 'zod';
import { JsonSchema7Type } from '../parseDef';
import { Refs } from '../Refs';
import { JsonSchema7NullType } from './null';
export type JsonSchema7NullableType = {
    anyOf: [JsonSchema7Type, JsonSchema7NullType];
} | {
    type: [string, 'null'];
};
export declare function parseNullableDef(def: ZodNullableDef, refs: Refs): JsonSchema7NullableType | undefined;