TypeError when using match with a string

[mlntdrv]

import { match, mock, when } from 'ts-mockito';
import { SomeClass } from 'some-class';
import { Observable } from 'rxjs';

const SomeClassMock: SomeClass = mock(SomeClass);

when(SomeClassMock.method<boolean>(match('/x/y/'))).thenReturn(
  new Observable<boolean>()
);

TypeError: Cannot read property 'match' of null
at MatchingStringMatcher.match (.../node_modules/ts-mockito/src/matcher/type/MatchingStringMatcher.ts:9:22)
at .../node_modules/ts-mockito/src/matcher/ArgsToMatchersValidator.ts:8:76
at Array.every ()
at ArgsToMatchersValidator.validate (.../node_modules/ts-mockito/src/matcher/ArgsToMatchersValidator.ts:8:25)
at ReturnValueMethodStub.isApplicable (.../node_modules/ts-mockito/src/stub/ReturnValueMethodStub.ts:14:31)
at .../node_modules/ts-mockito/src/MethodStubCollection.ts:23:59
at Array.some ()
at MethodStubCollection.hasMatchingInAnyGroup (.../node_modules/ts-mockito/src/MethodStubCollection.ts:23:27)
at Mocker.getMethodStub (.../node_modules/ts-mockito/src/Mock.ts:238:38)
at Proxy. (.../node_modules/ts-mockito/src/Mock.ts:161:37)