diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c512e49..41a2dde 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -12,13 +12,16 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
 
     steps:
       - uses: actions/checkout@v4
-      - name: Set up Python 3.9
+      - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
diff --git a/poetry.lock b/poetry.lock
index 90bb93b..09c00e6 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -717,4 +717,4 @@ files = [
 [metadata]
 lock-version = "2.1"
 python-versions = ">=3.9"
-content-hash = "8fc64de4f55b234589828215b2dca5a673f1772127f00a7eb4708a634ed109a4"
+content-hash = "62ec508e60ef0cd1493ae96955f6d3c7cd0b72dd6b5c55a598e6f101f18a5b2b"
diff --git a/pyproject.toml b/pyproject.toml
index a08d5c4..8cee54d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,8 +12,8 @@ license = "MIT"
 requires-python = ">=3.9"
 
 dependencies = [
-    "icalendar (~=6.0)",
-    "python-dateutil (~=2.9)",
+    "icalendar (>=5.0.3)",
+    "python-dateutil (>=2.9)",
     "pytz (>=2024.2)",
     "urllib3 (>=1.26.5)",
 ]