diff --git a/src/github.com/matrix-org/dendrite/mediaapi/README.md b/src/github.com/matrix-org/dendrite/mediaapi/README.md
index ab62fae23..8a32263bb 100644
--- a/src/github.com/matrix-org/dendrite/mediaapi/README.md
+++ b/src/github.com/matrix-org/dendrite/mediaapi/README.md
@@ -4,4 +4,6 @@ This server is responsible for serving `/media` requests as per:
 
 http://matrix.org/docs/spec/client_server/r0.2.0.html#id43
 
-Thumbnailing uses bimg from https://github.com/h2non/bimg (MIT-licensed) which uses libvips from https://github.com/jcupitt/libvips (LGPL v2.1+ -licensed). libvips is a C library and must be installed/built separately. See the github page for details.
+Thumbnailing uses https://github.com/nfnt/resize by default which is a pure golang image scaling library relying on image codecs from the standard library. It is ISC-licensed.
+
+Alternatively one can use `gb build -tags bimg` to use bimg from https://github.com/h2non/bimg (MIT-licensed) which uses libvips from https://github.com/jcupitt/libvips (LGPL v2.1+ -licensed). libvips is a C library and must be installed/built separately. See the github page for details. Also note that libvips in turn has dependencies with a selection of FOSS licenses. bimg and libvips have significantly better performance than nfnt/resize.