diff --git a/CHANGELOG.md b/CHANGELOG.md
index 45adf87e..682db20b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,13 @@ The format is based on [Keep a
 Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.1.3 - 2021-07-02
+
+### Fixed
+
+- Switch from using `Bitwise.bor/2` to `:erlang.bor/2` for compatibility
+  with Elixir < 1.10
+
 ## 0.1.2 - 2021-07-02
 
 ### Fixed
diff --git a/lib/mint/web_socket/per_message_deflate.ex b/lib/mint/web_socket/per_message_deflate.ex
index 543a6a2f..e7b79a0a 100644
--- a/lib/mint/web_socket/per_message_deflate.ex
+++ b/lib/mint/web_socket/per_message_deflate.ex
@@ -122,7 +122,7 @@ defmodule Mint.WebSocket.PerMessageDeflate do
 
       frame =
         Frame.unquote(opcode)(frame,
-          reserved: <<Bitwise.bor(reserved, 0b100)::size(3)>>,
+          reserved: <<:erlang.bor(reserved, 0b100)::size(3)>>,
           data: data
         )