README: link to the newish `cmp` package
diff --git a/README.md b/README.md
index dc5ec73..f225f48 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,7 @@
 --------------
 
 If `godebug/pretty` is not granular enough, I highly recommend
-checking out [go-spew][spew].
+checking out [cmp][cmp] or [go-spew][spew].
 
+[cmp]: https://godoc.org/github.com/google/go-cmp/cmp
 [spew]: http://godoc.org/github.com/davecgh/go-spew/spew