diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4f62148f..a0e1aae2 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -61,3 +61,32 @@ jobs:
 
     - name: Run simple code
       run: python -c 'import math; print(math.factorial(5))'
+
+  setup-pre-release-version-from-manifest:
+    name: Setup 3.9.0-beta.4 ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, windows-latest, ubuntu-16.04, ubuntu-18.04]
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: setup-python 3.9.0-beta.4
+      uses: ./
+      with:
+        python-version: '3.9.0-beta.4'
+
+    - name: Validate version
+      run: |
+        $pythonVersion = (python --version)
+        if ("Python ${{ matrix.python }}" -ne "$pythonVersion"){
+          Write-Host "The current version is $pythonVersion; expected version is ${{ matrix.python }}"
+          exit 1
+        }
+        $pythonVersion
+      shell: pwsh
+
+    - name: Run simple code
+      run: python -c 'import math; print(math.factorial(5))'
diff --git a/README.md b/README.md
index b7146fdb..8cec2221 100644
--- a/README.md
+++ b/README.md
@@ -99,7 +99,6 @@ steps:
 - uses: actions/setup-python@v2
   with:
     python-version: '3.9.0-beta.4'
-    stable: false # optional true or false. Defaults to true if not specified
 - run: python my_script.py
 ```
 
@@ -110,7 +109,6 @@ steps:
 - uses: actions/setup-python@v2
   with:
     python-version: '3.9.0-alpha - 3.9.0' # SemVer's version range syntax
-    stable: false # optional true or false. Defaults to true if not specified
 - run: python my_script.py
 ```
 
diff --git a/__tests__/finder.test.ts b/__tests__/finder.test.ts
index b3a8df13..54bf3cf8 100644
--- a/__tests__/finder.test.ts
+++ b/__tests__/finder.test.ts
@@ -35,7 +35,7 @@ describe('Finder tests', () => {
     await io.mkdirP(pythonDir);
     fs.writeFileSync(`${pythonDir}.complete`, 'hello');
     // This will throw if it doesn't find it in the cache and in the manifest (because no such version exists)
-    await finder.findPythonVersion('3.x', 'x64', true);
+    await finder.findPythonVersion('3.x', 'x64');
   });
 
   it('Finds stable Python version if it is not installed, but exists in the manifest', async () => {
@@ -52,7 +52,7 @@ describe('Finder tests', () => {
       fs.writeFileSync(`${pythonDir}.complete`, 'hello');
     });
     // This will throw if it doesn't find it in the cache and in the manifest (because no such version exists)
-    await finder.findPythonVersion('1.2.3', 'x64', true);
+    await finder.findPythonVersion('1.2.3', 'x64');
   });
 
   it('Finds pre-release Python version in the manifest', async () => {
@@ -74,14 +74,14 @@ describe('Finder tests', () => {
       fs.writeFileSync(`${pythonDir}.complete`, 'hello');
     });
     // This will throw if it doesn't find it in the manifest (because no such version exists)
-    await finder.findPythonVersion('1.2.3-beta.2', 'x64', false);
+    await finder.findPythonVersion('1.2.3-beta.2', 'x64');
   });
 
   it('Errors if Python is not installed', async () => {
     // This will throw if it doesn't find it in the cache and in the manifest (because no such version exists)
     let thrown = false;
     try {
-      await finder.findPythonVersion('3.300000', 'x64', true);
+      await finder.findPythonVersion('3.300000', 'x64');
     } catch {
       thrown = true;
     }
@@ -93,6 +93,6 @@ describe('Finder tests', () => {
     await io.mkdirP(pythonDir);
     fs.writeFileSync(`${pythonDir}.complete`, 'hello');
     // This will throw if it doesn't find it in the cache (because no such version exists)
-    await finder.findPythonVersion('pypy2', 'x64', true);
+    await finder.findPythonVersion('pypy2', 'x64');
   });
 });
diff --git a/action.yml b/action.yml
index 4d1098f1..b5dcf476 100644
--- a/action.yml
+++ b/action.yml
@@ -8,9 +8,6 @@ inputs:
     default: '3.x'
   architecture:
     description: 'The target architecture (x86, x64) of the Python interpreter.'
-  stable:
-    description: 'Whether to download only stable versions'
-    default: 'true'
   token:
     description: Used to pull python distributions from actions/python-versions. Since there's a default, this is typically not supplied by the user.
     default: ${{ github.token }}
diff --git a/dist/index.js b/dist/index.js
index bd08caa9..5ff593ff 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1143,10 +1143,10 @@ const MANIFEST_REPO_NAME = 'python-versions';
 const MANIFEST_REPO_BRANCH = 'main';
 exports.MANIFEST_URL = `https://raw.githubusercontent.com/${MANIFEST_REPO_OWNER}/${MANIFEST_REPO_NAME}/${MANIFEST_REPO_BRANCH}/versions-manifest.json`;
 const IS_WINDOWS = process.platform === 'win32';
-function findReleaseFromManifest(semanticVersionSpec, architecture, stable) {
+function findReleaseFromManifest(semanticVersionSpec, architecture) {
     return __awaiter(this, void 0, void 0, function* () {
         const manifest = yield tc.getManifestFromRepo(MANIFEST_REPO_OWNER, MANIFEST_REPO_NAME, AUTH, MANIFEST_REPO_BRANCH);
-        return yield tc.findFromManifest(semanticVersionSpec, stable, manifest, architecture);
+        return yield tc.findFromManifest(semanticVersionSpec, false, manifest, architecture);
     });
 }
 exports.findReleaseFromManifest = findReleaseFromManifest;
@@ -1627,8 +1627,7 @@ function run() {
             let version = core.getInput('python-version');
             if (version) {
                 const arch = core.getInput('architecture') || os.arch();
-                let stable = (core.getInput('stable') || 'true').toUpperCase() === 'TRUE';
-                const installed = yield finder.findPythonVersion(version, arch, stable);
+                const installed = yield finder.findPythonVersion(version, arch);
                 core.info(`Successfully setup ${installed.impl} (${installed.version})`);
             }
             const matchersPath = path.join(__dirname, '..', '.github');
@@ -2308,7 +2307,7 @@ function usePyPy(majorVersion, architecture) {
     core.setOutput('python-version', impl);
     return { impl: impl, version: versionFromPath(installDir) };
 }
-function useCpythonVersion(version, architecture, stable) {
+function useCpythonVersion(version, architecture) {
     return __awaiter(this, void 0, void 0, function* () {
         const desugaredVersionSpec = desugarDevVersion(version);
         const semanticVersionSpec = pythonVersionToSemantic(desugaredVersionSpec);
@@ -2316,7 +2315,7 @@ function useCpythonVersion(version, architecture, stable) {
         let installDir = tc.find('Python', semanticVersionSpec, architecture);
         if (!installDir) {
             core.info(`Version ${semanticVersionSpec} was not found in the local cache`);
-            const foundRelease = yield installer.findReleaseFromManifest(semanticVersionSpec, architecture, stable);
+            const foundRelease = yield installer.findReleaseFromManifest(semanticVersionSpec, architecture);
             if (foundRelease && foundRelease.files && foundRelease.files.length > 0) {
                 core.info(`Version ${semanticVersionSpec} is available for downloading`);
                 yield installer.installCpythonFromRelease(foundRelease);
@@ -2374,7 +2373,7 @@ function pythonVersionToSemantic(versionSpec) {
     return versionSpec.replace(prereleaseVersion, '$1-$2');
 }
 exports.pythonVersionToSemantic = pythonVersionToSemantic;
-function findPythonVersion(version, architecture, stable) {
+function findPythonVersion(version, architecture) {
     return __awaiter(this, void 0, void 0, function* () {
         switch (version.toUpperCase()) {
             case 'PYPY2':
@@ -2382,7 +2381,7 @@ function findPythonVersion(version, architecture, stable) {
             case 'PYPY3':
                 return usePyPy(3, architecture);
             default:
-                return yield useCpythonVersion(version, architecture, stable);
+                return yield useCpythonVersion(version, architecture);
         }
     });
 }
diff --git a/src/find-python.ts b/src/find-python.ts
index 7deec7d0..db06230d 100644
--- a/src/find-python.ts
+++ b/src/find-python.ts
@@ -71,8 +71,7 @@ function usePyPy(majorVersion: 2 | 3, architecture: string): InstalledVersion {
 
 async function useCpythonVersion(
   version: string,
-  architecture: string,
-  stable: boolean
+  architecture: string
 ): Promise<InstalledVersion> {
   const desugaredVersionSpec = desugarDevVersion(version);
   const semanticVersionSpec = pythonVersionToSemantic(desugaredVersionSpec);
@@ -89,8 +88,7 @@ async function useCpythonVersion(
     );
     const foundRelease = await installer.findReleaseFromManifest(
       semanticVersionSpec,
-      architecture,
-      stable
+      architecture
     );
 
     if (foundRelease && foundRelease.files && foundRelease.files.length > 0) {
@@ -173,8 +171,7 @@ export function pythonVersionToSemantic(versionSpec: string) {
 
 export async function findPythonVersion(
   version: string,
-  architecture: string,
-  stable: boolean
+  architecture: string
 ): Promise<InstalledVersion> {
   switch (version.toUpperCase()) {
     case 'PYPY2':
@@ -182,6 +179,6 @@ export async function findPythonVersion(
     case 'PYPY3':
       return usePyPy(3, architecture);
     default:
-      return await useCpythonVersion(version, architecture, stable);
+      return await useCpythonVersion(version, architecture);
   }
 }
diff --git a/src/install-python.ts b/src/install-python.ts
index 954d542d..1ec98d8d 100644
--- a/src/install-python.ts
+++ b/src/install-python.ts
@@ -15,8 +15,7 @@ const IS_WINDOWS = process.platform === 'win32';
 
 export async function findReleaseFromManifest(
   semanticVersionSpec: string,
-  architecture: string,
-  stable: boolean
+  architecture: string
 ): Promise<tc.IToolRelease | undefined> {
   const manifest: tc.IToolRelease[] = await tc.getManifestFromRepo(
     MANIFEST_REPO_OWNER,
@@ -26,7 +25,7 @@ export async function findReleaseFromManifest(
   );
   return await tc.findFromManifest(
     semanticVersionSpec,
-    stable,
+    false,
     manifest,
     architecture
   );
diff --git a/src/setup-python.ts b/src/setup-python.ts
index d46b281b..c97f314c 100644
--- a/src/setup-python.ts
+++ b/src/setup-python.ts
@@ -8,8 +8,7 @@ async function run() {
     let version = core.getInput('python-version');
     if (version) {
       const arch: string = core.getInput('architecture') || os.arch();
-      let stable = (core.getInput('stable') || 'true').toUpperCase() === 'TRUE';
-      const installed = await finder.findPythonVersion(version, arch, stable);
+      const installed = await finder.findPythonVersion(version, arch);
       core.info(`Successfully setup ${installed.impl} (${installed.version})`);
     }
     const matchersPath = path.join(__dirname, '..', '.github');