diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 5291d117..76b595a1 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -313,3 +313,16 @@ jobs:
           key: pre-commit|${{ hashFiles('.pre-commit-config.yaml') }}
       - run: pip install tox
       - run: tox -e style
+  deptry:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+      - uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: pip|${{ hashFiles('setup.py') }}|${{ hashFiles('tox.ini') }}
+      - run: pip install tox
+      - run: tox -e deptry
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd88ef50..c50ffd8f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,13 @@ Changelogs prior to v1.2 is pruned, but available in the v1.2 release
 
 This project should adhere to [Semantic Versioning](https://semver.org/spec/v2.0.0.html), though some earlier releases may be incompatible with the SemVer standard.
 
+## [Unreleased]
+
+### Added
+
+* Added deptry for dependency verification in CI
+* Added python-dateutil and PyYAML as explicit dependencies (were transitive)
+
 ## [2.2.3] - [2025-12-06]
 
 ### Fixed
diff --git a/pyproject.toml b/pyproject.toml
index e208207e..40a3b6e0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -59,6 +59,8 @@ dependencies = [
   "icalendar>6.0.0",
   "icalendar-searcher>=1.0.0,<2",
   "dnspython",
+  "python-dateutil",
+  "PyYAML",
 ]
 dynamic = ["version"]
 
@@ -80,6 +82,7 @@ test = [
   "radicale",
   "pyfakefs",
   #"caldav_server_tester"
+  "deptry>=0.24.0; python_version >= '3.10'",
 ]
 [tool.setuptools_scm]
 write_to = "caldav/_version.py"
@@ -91,3 +94,9 @@ include-package-data = true
 [tool.setuptools.packages.find]
 exclude = ["tests"]
 namespaces = false
+
+[tool.deptry]
+ignore = ["DEP002"]  # Test dependencies (pytest, coverage, etc.) are not imported in main code
+
+[tool.deptry.per_rule_ignores]
+DEP001 = ["conf"]  # Local test configuration file, not a package
diff --git a/tox.ini b/tox.ini
index 33931b93..a8131b94 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox:tox]
-envlist = y39,py310,py311,py312,py313,py314,docs,style
+envlist = y39,py310,py311,py312,py313,py314,docs,style,deptry
 
 [testenv]
 deps = --editable .[test]
@@ -40,6 +40,11 @@ deps = pre-commit
 skip_install = true
 commands = pre-commit run --all-files --show-diff-on-failure
 
+[testenv:deptry]
+basepython = python3.13
+deps = --editable .[test]
+commands = deptry caldav --known-first-party caldav
+
 [build_sphinx]
 source-dir = docs/source
 build-dir = docs/build