diff --git a/.github/workflows/build-wheel.yml b/.github/workflows/build-wheel.yml
index 78f53b34..eccb5af4 100644
--- a/.github/workflows/build-wheel.yml
+++ b/.github/workflows/build-wheel.yml
@@ -68,7 +68,7 @@ jobs:
               \${PYBIN}/pip install --upgrade pip wheel &&
               \${PYBIN}/pip install toml==0.10.2 &&
               \${PYBIN}/pip install setuptools==68.0.0 &&
-              CFLAGS=\"-I/opt/python/cp310-cp310/include/python3.10\" LDFLAGS=\"-L/opt/python/cp310-cp310/lib\" \${PYBIN}/python setup.py bdist_wheel --plat-name $PLATFORM_TAG
+              CFLAGS=\"-I/opt/python/cp310-cp310/include/python3.9\" LDFLAGS=\"-L/opt/python/cp310-cp310/lib\" \${PYBIN}/python setup.py bdist_wheel --plat-name $PLATFORM_TAG
             done &&
             rm -f /io/dist/*-linux_*.whl
           "
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 87276b6c..232803eb 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -60,7 +60,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.9"
           cache: "pip"
 
       - name: Install project dependencies
@@ -114,7 +114,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.9"
           cache: "pip"
 
       - name: Install project dependencies
@@ -166,7 +166,7 @@ jobs:
     uses: ./.github/workflows/build-wheel.yml
     needs: [tests-unix, read-version]
     with:
-      python-version: "3.10"
+      python-version: "3.9"
       architecture: ${{ matrix.target }}
       artifact-name: wheels-linux-${{ matrix.target }}
       runs-on: ${{ matrix.runs-on }}
@@ -212,7 +212,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.9"
           cache: "pip"
 
       - name: Download wheel artifacts
@@ -251,7 +251,7 @@ jobs:
     uses: ./.github/workflows/build-wheel.yml
     needs: [tests-windows, read-version]
     with:
-      python-version: "3.10"
+      python-version: "3.9"
       architecture: ${{ matrix.target }}
       artifact-name: wheels-windows-${{ matrix.target }}
       runs-on: windows-latest
@@ -289,7 +289,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.9"
           cache: "pip"
 
       - name: Download wheel artifacts
@@ -330,7 +330,7 @@ jobs:
     uses: ./.github/workflows/build-wheel.yml
     needs: [tests-unix, read-version]
     with:
-      python-version: "3.10"
+      python-version: "3.9"
       runs-on: ${{ matrix.runs-on }}
       artifact-name: wheels-macos-${{ matrix.target }}
       architecture: ${{ matrix.target }}
@@ -380,7 +380,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.9"
           cache: "pip"
 
       - name: Download wheel artifacts
@@ -428,7 +428,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.9"
           cache: "pip"
       - name: Install dependencies
         run: pip install -r requirements.txt
diff --git a/README.md b/README.md
index d33472ee..f53a3430 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Features:
 
 ## Prerequisites
 
-This library requires Python version 3.10+.
+This library requires Python version 3.9+.
 
 ## Package installation
 
diff --git a/pyproject.toml b/pyproject.toml
index e3c873f6..91680ad1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "c2pa-python"
 version = "0.23.1"
-requires-python = ">=3.10"
+requires-python = ">=3.9"
 description = "Python bindings for the C2PA Content Authenticity Initiative (CAI) library"
 readme = { file = "README.md", content-type = "text/markdown" }
 license = { text = "MIT OR Apache-2.0" }
diff --git a/setup.py b/setup.py
index 489472c1..4e1f2318 100644
--- a/setup.py
+++ b/setup.py
@@ -217,7 +217,7 @@ def find_available_platforms():
                 "Programming Language :: Python :: 3",
                 get_platform_classifier(target_platform),
             ],
-            python_requires=">=3.10",
+            python_requires=">=3.9",
             long_description=open("README.md").read(),
             long_description_content_type="text/markdown",
             license="MIT OR Apache-2.0",
@@ -242,7 +242,7 @@ def find_available_platforms():
         "Programming Language :: Python :: 3",
         get_platform_classifier(get_current_platform()),
     ],
-    python_requires=">=3.10",
+    python_requires=">=3.9",
     long_description=open("README.md").read(),
     long_description_content_type="text/markdown",
     license="MIT OR Apache-2.0",