diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b40676b..85d1d25 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,8 +14,8 @@ jobs:
     name: CI on OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
     strategy:
       matrix:
-        otp: ['26']
-        elixir: ['1.16']
+        otp: ['29']
+        elixir: ['1.20']
     steps:
     - name: Set up Elixir
       uses: erlef/setup-beam@v1
diff --git a/README.md b/README.md
index 79d7416..db1fce8 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ Add `ex_rtp` to dependencies in `mix.exs`:
 ```elixir
 def deps do
   [
-    {:ex_rtp, "~> 0.4.0"}
+    {:ex_rtp, "~> 0.4.1"}
   ]
 end
 ```
diff --git a/lib/ex_rtp/packet.ex b/lib/ex_rtp/packet.ex
index 3061420..f81ff4e 100644
--- a/lib/ex_rtp/packet.ex
+++ b/lib/ex_rtp/packet.ex
@@ -202,10 +202,10 @@ defmodule ExRTP.Packet do
       when not is_list(extensions),
       do: packet
 
-  def remove_extension(packet, id) do
-    case Enum.reject(packet.extensions, &(&1.id == id)) do
-      [] -> %__MODULE__{packet | extension: false, extension_profile: nil, extensions: nil}
-      extensions -> %__MODULE__{packet | extensions: extensions}
+  def remove_extension(%__MODULE__{extensions: extensions} = packet, id) do
+    case Enum.reject(extensions, &(&1.id == id)) do
+      [] -> %{packet | extension: false, extension_profile: nil, extensions: nil}
+      extensions -> %{packet | extensions: extensions}
     end
   end
 
@@ -357,7 +357,7 @@ defmodule ExRTP.Packet do
   defp strip_padding(raw, packet) do
     size = byte_size(raw)
 
-    with <<_rest::binary-size(size - 1), len>> <- raw,
+    with <<_rest::binary-size(^size - 1), len>> <- raw,
          <<rest::binary-size(^size - ^len), _rest::binary>> <- raw do
       {:ok, rest, %{packet | padding_size: len}}
     else
diff --git a/mix.exs b/mix.exs
index 065cca2..85e12b6 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule ExRTP.MixProject do
   use Mix.Project
 
-  @version "0.4.0"
+  @version "0.4.1"
   @source_url "https://github.com/elixir-webrtc/ex_rtp"
 
   def project do
@@ -25,8 +25,13 @@ defmodule ExRTP.MixProject do
       ],
 
       # code coverage
-      test_coverage: [tool: ExCoveralls],
-      preferred_cli_env: [
+      test_coverage: [tool: ExCoveralls]
+    ]
+  end
+
+  def cli do
+    [
+      preferred_envs: [
         coveralls: :test,
         "coveralls.detail": :test,
         "coveralls.post": :test,
diff --git a/mix.lock b/mix.lock
index ce14e8f..b8a63d6 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,15 +1,15 @@
 %{
   "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
-  "credo": {:hex, :credo, "1.7.3", "05bb11eaf2f2b8db370ecaa6a6bda2ec49b2acd5e0418bc106b73b07128c0436", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "35ea675a094c934c22fb1dca3696f3c31f2728ae6ef5a53b5d648c11180a4535"},
-  "dialyxir": {:hex, :dialyxir, "1.4.3", "edd0124f358f0b9e95bfe53a9fcf806d615d8f838e2202a9f430d59566b6b53b", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "bf2cfb75cd5c5006bec30141b131663299c661a864ec7fbbc72dfa557487a986"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.39", "424642f8335b05bb9eb611aa1564c148a8ee35c9c8a8bba6e129d51a3e3c6769", [:mix], [], "hexpm", "06553a88d1f1846da9ef066b87b57c6f605552cfbe40d20bd8d59cc6bde41944"},
-  "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
-  "ex_doc": {:hex, :ex_doc, "0.31.0", "06eb1dfd787445d9cab9a45088405593dd3bb7fe99e097eaa71f37ba80c7a676", [:mix], [{:earmark_parser, "~> 1.4.39", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.1", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "5350cafa6b7f77bdd107aa2199fe277acf29d739aba5aee7e865fc680c62a110"},
-  "excoveralls": {:hex, :excoveralls, "0.18.0", "b92497e69465dc51bc37a6422226ee690ab437e4c06877e836f1c18daeb35da9", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "1109bb911f3cb583401760be49c02cbbd16aed66ea9509fc5479335d284da60b"},
-  "file_system": {:hex, :file_system, "1.0.0", "b689cc7dcee665f774de94b5a832e578bd7963c8e637ef940cd44327db7de2cd", [:mix], [], "hexpm", "6752092d66aec5a10e662aefeed8ddb9531d79db0bc145bb8c40325ca1d8536d"},
-  "jason": {:hex, :jason, "1.4.1", "af1504e35f629ddcdd6addb3513c3853991f694921b1b9368b0bd32beb9f1b63", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "fbb01ecdfd565b56261302f7e1fcc27c4fb8f32d56eab74db621fc154604a7a1"},
-  "makeup": {:hex, :makeup, "1.1.1", "fa0bc768698053b2b3869fa8a62616501ff9d11a562f3ce39580d60860c3a55e", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "5dc62fbdd0de44de194898b6710692490be74baa02d9d108bc29f007783b0b48"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.16.1", "cc9e3ca312f1cfeccc572b37a09980287e243648108384b97ff2b76e505c3555", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "e127a341ad1b209bd80f7bd1620a15693a9908ed780c3b763bccf7d200c767c6"},
-  "makeup_erlang": {:hex, :makeup_erlang, "0.1.3", "d684f4bac8690e70b06eb52dad65d26de2eefa44cd19d64a8095e1417df7c8fd", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "b78dc853d2e670ff6390b605d807263bf606da3c82be37f9d7f68635bd886fc9"},
-  "nimble_parsec": {:hex, :nimble_parsec, "1.4.0", "51f9b613ea62cfa97b25ccc2c1b4216e81df970acd8e16e8d1bdc58fef21370d", [:mix], [], "hexpm", "9c565862810fb383e9838c1dd2d7d2c437b3d13b267414ba6af33e50d2d1cf28"},
+  "credo": {:hex, :credo, "1.7.19", "cc52129665fc7c15143d47838fda0f9cd6dac9ceced7bf4da6f85fcbfe64b12a", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "2d8bc95d5a7bb99dd2613621d4f08c6a3575c3fd4b62e6a2b48a100352a557b8"},
+  "dialyxir": {:hex, :dialyxir, "1.4.7", "dda948fcee52962e4b6c5b4b16b2d8fa7d50d8645bbae8b8685c3f9ecb7f5f4d", [:mix], [{:erlex, ">= 0.2.8", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "b34527202e6eb8cee198efec110996c25c5898f43a4094df157f8d28f27d9efe"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
+  "erlex": {:hex, :erlex, "0.2.9", "7debbbaa9f4f368b8cd648983e0f1d7963028508e9c59e9d4ed504e94ef52a55", [:mix], [], "hexpm", "8cfffc0ec7159e6d73de2ab28a588064de80f88b2798d5cbe4482cbbc200178b"},
+  "ex_doc": {:hex, :ex_doc, "0.40.3", "4a972ffe64bc07dc605af487e98fc19b72a4185f55ca031b94c0552d6071c1d9", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "2756e357742fecd9749b489b85d67c9ce99c465f2e75728d9e6dc8d704b973de"},
+  "excoveralls": {:hex, :excoveralls, "0.18.5", "e229d0a65982613332ec30f07940038fe451a2e5b29bce2a5022165f0c9b157e", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "523fe8a15603f86d64852aab2abe8ddbd78e68579c8525ae765facc5eae01562"},
+  "file_system": {:hex, :file_system, "1.1.1", "31864f4685b0148f25bd3fbef2b1228457c0c89024ad67f7a81a3ffbc0bbad3a", [:mix], [], "hexpm", "7a15ff97dfe526aeefb090a7a9d3d03aa907e100e262a0f8f7746b78f8f87a5d"},
+  "jason": {:hex, :jason, "1.4.5", "2e3a008590b0b8d7388c20293e9dcc9cf3e5d642fd2a114e4cbbb52e595d940a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0 or ~> 3.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "b0c823996102bcd0239b3c2444eb00409b72f6a140c1950bc8b457d836b30684"},
+  "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
+  "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
+  "makeup_erlang": {:hex, :makeup_erlang, "1.1.0", "835f7e60792e08824cda445639555d7bf1bbbddb1b60b306e33cb6f6db24dc74", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "1cd6780fb1dd1a03979abaed0fe82712b0625118fd5257d3ebbf73f960c73c3c"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.4.2", "8efba0122db06df95bfaa78f791344a89352ba04baedd3849593bfce4d0dc1c6", [:mix], [], "hexpm", "4b21398942dda052b403bbe1da991ccd03a053668d147d53fb8c4e0efe09c973"},
 }