diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f45ee611..da22ee48 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,7 +3,7 @@ name: ci
 on: [push, pull_request]
 
 env:
-  X_PYTHON_MIN_VERSION: "3.9"
+  X_PYTHON_MIN_VERSION: "3.10"
   X_PYTHON_MAX_VERSION: "3.12"
 
 jobs:
@@ -45,7 +45,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.9", "3.12"]
+        python-version: ["3.10", "3.12"]
     env:
       COUCHDB_ADMIN_PASSWORD: "yo0Quai3"
       # (2024-10-11, s-heppner)
@@ -208,7 +208,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.9", "3.12"]
+        python-version: ["3.10", "3.12"]
     defaults:
       run:
         working-directory: ./compliance_tool
diff --git a/compliance_tool/pyproject.toml b/compliance_tool/pyproject.toml
index c907f90d..e235bdc9 100644
--- a/compliance_tool/pyproject.toml
+++ b/compliance_tool/pyproject.toml
@@ -34,7 +34,7 @@ classifiers = [
     "Operating System :: OS Independent",
     "Development Status :: 5 - Production/Stable"
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "pyecma376-2>=0.2.4",
     "jsonschema>=4.21.1",
diff --git a/sdk/.readthedocs.yaml b/sdk/.readthedocs.yaml
index 1085208a..7fd098a4 100644
--- a/sdk/.readthedocs.yaml
+++ b/sdk/.readthedocs.yaml
@@ -6,7 +6,7 @@ version: 2
 build:
   os: ubuntu-20.04
   tools:
-    python: "3.9"
+    python: "3.10"
 
 sphinx:
    configuration: docs/source/conf.py
diff --git a/sdk/pyproject.toml b/sdk/pyproject.toml
index 588d1840..b2a7a6b7 100644
--- a/sdk/pyproject.toml
+++ b/sdk/pyproject.toml
@@ -34,7 +34,7 @@ classifiers = [
     "Operating System :: OS Independent",
     "Development Status :: 5 - Production/Stable"
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "lxml>=6.0.2",
     "python-dateutil>=2.8,<3",
diff --git a/server/app/pyproject.toml b/server/app/pyproject.toml
index abaae73d..030be739 100644
--- a/server/app/pyproject.toml
+++ b/server/app/pyproject.toml
@@ -34,7 +34,7 @@ classifiers = [
     "Operating System :: OS Independent",
     "Development Status :: 5 - Production/Stable"
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "urllib3>=1.26,<3",
     "Werkzeug>=3.0.3,<4",