diff --git a/src/ws/tiny_httpd_ws.ml b/src/ws/tiny_httpd_ws.ml
index 3cc33c02..d886d57f 100644
--- a/src/ws/tiny_httpd_ws.ml
+++ b/src/ws/tiny_httpd_ws.ml
@@ -242,7 +242,7 @@ module Reader = struct
       let len = b1 land 0b0111_1111 in
       if len = 126 then (
         IO.Input.really_input self.ic self.header_buf 0 2;
-        Bytes.get_int16_be self.header_buf 0
+        Bytes.get_uint16_be self.header_buf 0
       ) else if len = 127 then (
         IO.Input.really_input self.ic self.header_buf 0 8;
         let len64 = Bytes.get_int64_be self.header_buf 0 in