diff --git a/http2/frame.go b/http2/frame.go
index c1f6b90dc..e2b298d85 100644
--- a/http2/frame.go
+++ b/http2/frame.go
@@ -1510,13 +1510,12 @@ func (mh *MetaHeadersFrame) checkPseudos() error {
 }
 
 func (fr *Framer) maxHeaderStringLen() int {
-	v := fr.maxHeaderListSize()
-	if uint32(int(v)) == v {
-		return int(v)
+	v := int(fr.maxHeaderListSize())
+	if v < 0 {
+		// If maxHeaderListSize overflows an int, use no limit (0).
+		return 0
 	}
-	// They had a crazy big number for MaxHeaderBytes anyway,
-	// so give them unlimited header lengths:
-	return 0
+	return v
 }
 
 // readMetaFrame returns 0 or more CONTINUATION frames from fr and