diff --git a/CHANGES.md b/CHANGES.md
index 21dd733..58a3ca1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,8 @@ Changes
 1.3.5.14 (unreleased)
 ---------------------
 
+- Add deprecation notice now that Koppeltaal-1 is no longer.
+
 - #80 Enable two SSO related tests on GitHub Actions again.
 
 1.3.5.13 (2021-05-05)
diff --git a/README.md b/README.md
index 79d1fac..db882e5 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
-![Run Koppeltaal Python Adapter tests](https://github.com/Koppeltaal/Koppeltaal-Python-Connector/workflows/Run%20Koppeltaal%20Python%20Adapter%20tests/badge.svg)
-
 Koppeltaal Python connector
 ===========================
 
+**Warning:** This code is for the so-called Koppeltaal-1 specification. As of Dec 31 2024 all Koppeltaal-1 technical infrastructure is decomissioned and this code base is obsolete. It is left here for historical purposes.
+
 “Koppeltaal” (Ducth for "Connect language") is a technical solution based on
 the international HL7/FHIR standard. It enables the exchange of e-health
 interventions. Koppeltaal enables organizations to connect e-health