diff --git a/pyproject.toml b/pyproject.toml
index 2adf80e6..b304bc18 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,7 +62,7 @@ optional-dependencies.bench = [
   "py-cpuinfo",
 ]
 optional-dependencies.calendar = [
-  "caldav>=2.2.6,<3",
+  "caldav>=3,<4",
 ]
 optional-dependencies.dev = [
   "nc-py-api[bench,calendar,dev-min]",