Rear Taillight for 2000 Monster 900

[Blue]

I decided to change my rear taillight on my Monster and when I removed the lens, there was no gasket between the lens and the base.  This surprised me as other bikes that I have owned have had a gasket there to seal the assembly.  There was also water/grime residue inside the lens from riding in the elements (Clear Alternatives lens).  I checked the parts catalog and there appears not to be a gasket there.  Is this true; was it added later or is this not an issue?  Thanks.
From the parts book for the bike:

[Slide Panda]

2 monsters, no gaskets...

[Blue]

2 monsters, no gaskets...

Thanks!  I will not worry about it then.