diff --git a/lib/manager/composer/lock-file.js b/lib/manager/composer/lock-file.js
index 003fa92e37c1dec447d51c40c5716c5c68c383de..837bedc849adfe13a874e7c235461d8426b2d091 100644
--- a/lib/manager/composer/lock-file.js
+++ b/lib/manager/composer/lock-file.js
@@ -29,7 +29,9 @@ async function getLockFile(
     await fs.outputFile(composerLockFileName, existingComposerLockContent);
     const env = { HOME: process.env.HOME, PATH: process.env.PATH };
     const startTime = process.hrtime();
-    const cmd = ('composer update ' + updatedDeps.join(' ')).trim();
+    const cmd =
+      ('composer update ' + updatedDeps.join(' ')).trim() +
+      ' --ignore-platform-reqs';
     logger.debug({ cmd });
     ({ stdout, stderr } = await exec(cmd, {
       cwd: tmpDir.path,