diff --git a/pkgs/development/python-modules/caldav/default.nix b/pkgs/development/python-modules/caldav/default.nix
index 27b59cfc07e..c2ffe1786c4 100644
--- a/pkgs/development/python-modules/caldav/default.nix
+++ b/pkgs/development/python-modules/caldav/default.nix
@@ -14,13 +14,13 @@
 
 buildPythonPackage rec {
   pname = "caldav";
-  version = "0.8.2";
+  version = "0.9.0";
 
   src = fetchFromGitHub {
     owner = "python-caldav";
     repo = pname;
-    rev = "v${version}";
-    hash = "sha256-2mpE1aLipps4X/3EF0oKHXDcrgUh78/fxY6y1B1V2IU=";
+    rev = "refs/tags/v${version}";
+    hash = "sha256-1pYbL9k2cfjIw9AFiItlDCidxZIuOAoUcgFmSibkphA=";
   };
 
   propagatedBuildInputs = [