Content-Type charset and compression

I have an issue with several MIME types, for which I want to set charset in their respective Content-Type header. One of them is regular "image/svg+xml". It looks like the only way to apply charset to the header is to manually modify file so that it will have a line like
Apache config:
svg, svgz = image/svg+xml; charset=utf-8
But, in this case compression is not applied. Looks like content type is checked against "image/svg+xml" in the compression settings, so it mismatches and thus is not applied. If I remove the charset from - compression is applied as expected.

Any suggestions on how to get both charset and compression?