diff --git a/blockservice/worker/bench/main.go b/blockservice/worker/bench/main.go
index 82c3dee13..c23770f78 100644
--- a/blockservice/worker/bench/main.go
+++ b/blockservice/worker/bench/main.go
@@ -1,3 +1,12 @@
+/*
+Benchmark github.com/ipfs/go-ipfs/blockservice/worker.
+
+Loop over a range of workers and buffer sizes and measure the time it
+per block-transfer operation for each value.  Run with:
+
+  $ go run "${GOPATH}/src/github.com/ipfs/go-ipfs/blockservice/worker/bench/main.go"
+*/
+
 package main
 
 import (