diff --git a/http3/request.go b/http3/request.go
index 9af25a57..126d34f1 100644
--- a/http3/request.go
+++ b/http3/request.go
@@ -83,10 +83,12 @@ func requestFromHeaders(headers []qpack.HeaderField) (*http.Request, error) {
 
 	var contentLength int64
 	if len(contentLengthStr) > 0 {
-		contentLength, err = strconv.ParseInt(contentLengthStr, 10, 64)
+		cl, err := strconv.ParseInt(contentLengthStr, 10, 64)
 		if err != nil {
 			return nil, err
 		}
+		httpHeaders.Set("Content-Length", contentLengthStr)
+		contentLength = cl
 	}
 
 	return &http.Request{
diff --git a/http3/request_test.go b/http3/request_test.go
index ce6262a7..edaef9df 100644
--- a/http3/request_test.go
+++ b/http3/request_test.go
@@ -26,7 +26,8 @@ var _ = Describe("Request", func() {
 		Expect(req.ProtoMajor).To(Equal(3))
 		Expect(req.ProtoMinor).To(BeZero())
 		Expect(req.ContentLength).To(Equal(int64(42)))
-		Expect(req.Header).To(BeEmpty())
+		Expect(req.Header).To(HaveLen(1))
+		Expect(req.Header.Get("Content-Length")).To(Equal("42"))
 		Expect(req.Body).To(BeNil())
 		Expect(req.Host).To(Equal("quic.clemente.io"))
 		Expect(req.RequestURI).To(Equal("/foo"))