diff --git a/__tests__/utils.test.ts b/__tests__/utils.test.ts
index 21feea57..f64be9bf 100644
--- a/__tests__/utils.test.ts
+++ b/__tests__/utils.test.ts
@@ -282,6 +282,24 @@ describe('Utils tests', () => {
     process.env['php-version'] = '8.2';
     expect(await utils.readPHPVersion()).toBe('8.2');
 
+    delete process.env['php-version-file'];
+    delete process.env['php-version'];
+
+    existsSync.mockReturnValueOnce(false).mockReturnValueOnce(true);
+    readFileSync.mockReturnValue(
+      '{ "platform-overrides": { "php": "7.3.25" } }'
+    );
+    expect(await utils.readPHPVersion()).toBe('7.3.25');
+
+    existsSync
+      .mockReturnValueOnce(false)
+      .mockReturnValueOnce(false)
+      .mockReturnValueOnce(true);
+    readFileSync.mockReturnValue(
+      '{ "config": { "platform": { "php": "7.4.33" } } }'
+    );
+    expect(await utils.readPHPVersion()).toBe('7.4.33');
+
     existsSync.mockClear();
     readFileSync.mockClear();
   });
diff --git a/dist/index.js b/dist/index.js
index 4a719438..c61b659a 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1371,6 +1371,23 @@ async function readPHPVersion() {
     else if (versionFile !== '.php-version') {
         throw new Error(`Could not find '${versionFile}' file.`);
     }
+    const composerLock = 'composer.lock';
+    if (fs_1.default.existsSync(composerLock)) {
+        const lockFileContents = JSON.parse(fs_1.default.readFileSync(composerLock, 'utf8'));
+        if (lockFileContents['platform-overrides'] &&
+            lockFileContents['platform-overrides']['php']) {
+            return lockFileContents['platform-overrides']['php'];
+        }
+    }
+    const composerJson = 'composer.json';
+    if (fs_1.default.existsSync(composerJson)) {
+        const composerFileContents = JSON.parse(fs_1.default.readFileSync(composerJson, 'utf8'));
+        if (composerFileContents['config'] &&
+            composerFileContents['config']['platform'] &&
+            composerFileContents['config']['platform']['php']) {
+            return composerFileContents['config']['platform']['php'];
+        }
+    }
     return 'latest';
 }
 exports.readPHPVersion = readPHPVersion;
diff --git a/src/utils.ts b/src/utils.ts
index e25928a4..c42b9310 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -440,6 +440,32 @@ export async function readPHPVersion(): Promise<string> {
   } else if (versionFile !== '.php-version') {
     throw new Error(`Could not find '${versionFile}' file.`);
   }
+
+  const composerLock = 'composer.lock';
+  if (fs.existsSync(composerLock)) {
+    const lockFileContents = JSON.parse(fs.readFileSync(composerLock, 'utf8'));
+    if (
+      lockFileContents['platform-overrides'] &&
+      lockFileContents['platform-overrides']['php']
+    ) {
+      return lockFileContents['platform-overrides']['php'];
+    }
+  }
+
+  const composerJson = 'composer.json';
+  if (fs.existsSync(composerJson)) {
+    const composerFileContents = JSON.parse(
+      fs.readFileSync(composerJson, 'utf8')
+    );
+    if (
+      composerFileContents['config'] &&
+      composerFileContents['config']['platform'] &&
+      composerFileContents['config']['platform']['php']
+    ) {
+      return composerFileContents['config']['platform']['php'];
+    }
+  }
+
   return 'latest';
 }