diff --git a/src/pkg/http/fs.go b/src/pkg/http/fs.go
index b3cae19a50d..bbfa58d264d 100644
--- a/src/pkg/http/fs.go
+++ b/src/pkg/http/fs.go
@@ -166,7 +166,7 @@ func serveFile(w ResponseWriter, r *Request, name string, redirect bool) {
 		}
 		size = ra.length
 		code = StatusPartialContent
-		w.SetHeader("Content-Range", fmt.Sprintf("%d-%d/%d", ra.start, ra.start+ra.length, d.Size))
+		w.SetHeader("Content-Range", fmt.Sprintf("bytes %d-%d/%d", ra.start, ra.start+ra.length-1, d.Size))
 	}
 
 	w.SetHeader("Accept-Ranges", "bytes")
diff --git a/src/pkg/http/fs_test.go b/src/pkg/http/fs_test.go
index 0f71356926c..0a5636b88d1 100644
--- a/src/pkg/http/fs_test.go
+++ b/src/pkg/http/fs_test.go
@@ -134,7 +134,7 @@ func TestServeFile(t *testing.T) {
 		if rt.code == StatusRequestedRangeNotSatisfiable {
 			continue
 		}
-		h := fmt.Sprintf("%d-%d/%d", rt.start, rt.end, testFileLength)
+		h := fmt.Sprintf("bytes %d-%d/%d", rt.start, rt.end-1, testFileLength)
 		if rt.r == "" {
 			h = ""
 		}
diff --git a/src/pkg/http/server.go b/src/pkg/http/server.go
index 2ecdd5ee258..644724f58e6 100644
--- a/src/pkg/http/server.go
+++ b/src/pkg/http/server.go
@@ -229,6 +229,10 @@ func (w *response) WriteHeader(code int) {
 		w.header["Transfer-Encoding"] = "", false
 		w.chunking = false
 	}
+	// Cannot use Content-Length with non-identity Transfer-Encoding.
+	if w.chunking {
+		w.header["Content-Length"] = "", false
+	}
 	if !w.req.ProtoAtLeast(1, 0) {
 		return
 	}