diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 496e597..fe4ee3b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        otp: [22.0.7, 22.1.8, 22.2.8, 22.3.4.14, 23.0.4, 23.1.5.0, 23.2.1.0, 24.0.2]
+        otp: [24.3.4, 25.0.4.0, 25.1.2]
     container:
       image: erlang:${{ matrix.otp }}-alpine
     steps:
@@ -47,7 +47,7 @@ jobs:
 
   slack:
     needs: test
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     if: always()
     steps:
     - name: Slack notification
@@ -65,7 +65,7 @@ jobs:
 
   finish:
     needs: test
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     if: always()
     steps:
     - name: Coveralls Finished
diff --git a/NEWS.md b/NEWS.md
index 961b1f2..ad7f4f4 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -3,6 +3,19 @@ gtplib
 
 Erlang library for encoding and decoding GTPv1, GTPv2 and GTP' frames.
 
+Version 4.0.0 - 01 December 2022
+--------------------------------
+
+Major version changed to 4.0 due to incompatible API change in decoding of flags in information elements.
+
+**Features** :rocket:
+* [#42](https://github.com/travelping/gtplib/pull/42) add [OpenTelemetry](https://opentelemetry.io/) helpers
+  to convert GTP messages into OpenTelemetry attributes.
+* [#43](https://github.com/travelping/gtplib/pull/43) convert all GTP flag fields from lists to maps
+
+**Features** :rocket:
+* [#39](https://github.com/travelping/gtplib/pull/39) Exporting `ULI`, `RAI` encoding functions and decoding functions
+
 Version 3.2.0 - 22 September 2022
 ---------------------------
 
diff --git a/README.md b/README.md
index a0f0bd4..d0f220d 100644
--- a/README.md
+++ b/README.md
@@ -7,9 +7,6 @@ gtplib
 [![Erlang Versions][erlang version badge]][gh]
 
 Erlang library for encoding and decoding GTPv1, GTPv2 and GTP' frames.
-Erlang netlink wrapper for talking the Linux kernel GTP-U module
-(devel version: https://github.com/RoadRunnr/osmo-ggsn,
- upstream:      http://git.osmocom.org/osmo-gtp-kernel/)
 
 BUILDING
 --------
@@ -18,6 +15,13 @@ Using rebar:
 
     # rebar3 compile
 
+# ERLANG Version Support
+
+OTP 24.3 is current the minimum supported version. Older versions might work but are no longer tested.
+
+When in doubt check the `matrix.otpe` setting in [.github/workflows/main.yml](.github/workflows/main.yml) for tested
+versions.
+
 <!-- Badges -->
 [hexpm]: https://hex.pm/packages/gtplib
 [hexpm version]: https://img.shields.io/hexpm/v/gtplib.svg?style=flat-square
@@ -26,4 +30,4 @@ Using rebar:
 [gh badge]: https://img.shields.io/github/workflow/status/travelping/gtplib/CI?style=flat-square
 [coveralls]: https://coveralls.io/github/travelping/gtplib
 [coveralls badge]: https://img.shields.io/coveralls/travelping/gtplib/master.svg?style=flat-square
-[erlang version badge]: https://img.shields.io/badge/erlang-21.3%20to%2023.2-blue.svg?style=flat-square
+[erlang version badge]: https://img.shields.io/badge/erlang-24.2%20to%2025.1-blue.svg?style=flat-square
diff --git a/rebar.config b/rebar.config
index 10df0fc..addfda6 100644
--- a/rebar.config
+++ b/rebar.config
@@ -9,7 +9,7 @@
 	{parse_trans, {git, "https://github.com/uwiger/parse_trans.git", {branch, "master"}}}
 ]}.
 
-{minimum_otp_vsn, "21.3"}.
+{minimum_otp_vsn, "24.3"}.
 {plugins, [rebar3_hex]}.
 
 {profiles, [