diff --git a/openhab-addons.nix b/openhab-addons.nix
index a3ec4e5..a0a62b4 100644
--- a/openhab-addons.nix
+++ b/openhab-addons.nix
@@ -4,6 +4,6 @@ let
     version = builtins.readFile ./version;
     sha256 = builtins.readFile ./openhab-addons.sha256;
 in fetchurl {
-    url = "https://github.com/openhab/openhab-distro/releases/download/${version}/openhab-addons-${version}.kar";
+    url = "https://github.com/openhab/openhab-distro/releases/download/4.2.0.M1/openhab-addons-4.2.1.M1.kar";
     inherit sha256;
 }
diff --git a/openhab.nix b/openhab.nix
index 090d44f..1ab387d 100644
--- a/openhab.nix
+++ b/openhab.nix
@@ -13,13 +13,13 @@
 }:
 
 let
-    version = builtins.readFile ./version;
-    sha256 = builtins.readFile ./openhab.sha256;
+    version = "4.2.0.M1";
+    sha256 = "a7e390b21abb476c17ac2976a77fed8c15b5b8b493ad34de0a2deb81a96bdf07";
 in stdenv.mkDerivation rec {
     inherit version;
     pname = "openhab";
     src = fetchurl {
-        url = "https://github.com/openhab/openhab-distro/releases/download/${version}/openhab-${version}.tar.gz";
+        url = "https://github.com/openhab/openhab-distro/releases/download/4.2.0.M1/openhab-4.2.0.M1.tar.gz";
         inherit sha256;
     };
     nativeBuildInputs = [ makeWrapper ];
diff --git a/openhab.sha256 b/openhab.sha256
index 85ca417..e4ac906 100644
--- a/openhab.sha256
+++ b/openhab.sha256
@@ -1 +1 @@
-8d6b3de2ab5711303055cee67288fcf761609bf902e97cc5e58a20856b63ba20
\ No newline at end of file
+a7e390b21abb476c17ac2976a77fed8c15b5b8b493ad34de0a2deb81a96bdf07
diff --git a/version b/version
index 2582ddd..350b968 100644
--- a/version
+++ b/version
@@ -1 +1 @@
-4.1.1
\ No newline at end of file
+4.2.0.M1