I'm trying to check whether an open generic type definition implements some open generic interface. Look at the sample below:

public interface IService<T> { }

public class ServiceImpl<T> : IService<T> { }

private static bool OpenGenericTypeImplementsOpenGenericInterface(
    Type derivedType, Type interfaceType)
{
    return derivedType.GetInterfaces().Contains(interfaceType);
}

[TestMethod]
public void Verify()
{
    Type openGenericImplementation = typeof(ServiceImpl<>);

    Type expectedInterfaceType = typeof(IService<>);

    bool implDoesImplementInterface = OpenGenericTypeImplementsOpenGenericInterface(
        openGenericImplementation, expectedInterfaceType);

    // This assert fails. Why?
    Assert.IsTrue(implDoesImplementInterface);
}

I found out that the returned type from the Type.GetInterfaces() method does not match the type returned from typeof(IService<>). I can't figure out why that is and how to correctly validate whether some generic type definition inherits or implements some other generic type definition.

What's going on here and how do I solve fix this problem?