diff --git a/packages/aws-cdk/lib/api/aws-auth/account-cache.ts b/packages/aws-cdk/lib/api/aws-auth/account-cache.ts
index 75082b9953966..30ac1704ccc36 100644
--- a/packages/aws-cdk/lib/api/aws-auth/account-cache.ts
+++ b/packages/aws-cdk/lib/api/aws-auth/account-cache.ts
@@ -83,6 +83,9 @@ export class AccountAccessKeyCache {
       // File doesn't exist or is not readable. This is a cache,
       // pretend we successfully loaded an empty map.
       if (e.code === 'ENOENT' || e.code === 'EACCES') { return {}; }
+      // File is not JSON, could be corrupted because of concurrent writes.
+      // Again, an empty cache is fine.
+      if (e instanceof SyntaxError) { return {}; }
       throw e;
     }
   }
diff --git a/packages/aws-cdk/test/account-cache.test.ts b/packages/aws-cdk/test/account-cache.test.ts
index f8860046df584..89887cc627d71 100644
--- a/packages/aws-cdk/test/account-cache.test.ts
+++ b/packages/aws-cdk/test/account-cache.test.ts
@@ -111,3 +111,14 @@ test(`cache is nuked if it exceeds ${AccountAccessKeyCache.MAX_ENTRIES} entries`
     await nukeCache(cacheDir);
   }
 });
+
+test('cache pretends to be empty if cache file does not contain JSON', async() => {
+  const { cacheDir, cacheFile, cache } = await makeCache();
+  try {
+    await fs.writeFile(cacheFile, '');
+
+    await expect(cache.get('abc')).resolves.toEqual(undefined);
+  } finally {
+    await nukeCache(cacheDir);
+  }
+});