diff --git a/lib/modules/manager/circleci/index.spec.ts b/lib/modules/manager/circleci/index.spec.ts
new file mode 100644
index 0000000000000000000000000000000000000000..527ffb6aa50e788b12b68510d774a6278d82ab07
--- /dev/null
+++ b/lib/modules/manager/circleci/index.spec.ts
@@ -0,0 +1,24 @@
+import { regexMatches } from '../../../../test/util';
+import { defaultConfig } from '.';
+
+describe('modules/manager/circleci/index', () => {
+  describe('file names match fileMatch', () => {
+    it.each`
+      path                           | expected
+      ${'.circleci/config.yml'}      | ${true}
+      ${'.circleci/config.yaml'}     | ${true}
+      ${'.circleci/foo.yaml'}        | ${true}
+      ${'.circleci/foo.yml'}         | ${true}
+      ${'.circleci/foo/config.yaml'} | ${true}
+      ${'.circleci/foo/bar.yml'}     | ${true}
+      ${'foo/.circleci/bar.yaml'}    | ${true}
+      ${'foo.yml'}                   | ${false}
+      ${'circleci/foo.yml'}          | ${false}
+      ${'circleci/foo.yml'}          | ${false}
+      ${'.circleci_foo/bar.yml'}     | ${false}
+      ${'.circleci/foo.toml'}        | ${false}
+    `('regexMatches("$path") === $expected', ({ path, expected }) => {
+      expect(regexMatches(path, defaultConfig.fileMatch)).toBe(expected);
+    });
+  });
+});
diff --git a/lib/modules/manager/circleci/index.ts b/lib/modules/manager/circleci/index.ts
index 3c2fb9b0532b2340fe212350e554a60bb713187e..353e21627b87954a06010a13e2a7001a9be8b245 100644
--- a/lib/modules/manager/circleci/index.ts
+++ b/lib/modules/manager/circleci/index.ts
@@ -10,7 +10,7 @@ export const displayName = 'CircleCI';
 export const url = 'https://circleci.com/docs/configuration-reference';
 
 export const defaultConfig = {
-  fileMatch: ['(^|/)\\.circleci/config\\.ya?ml$'],
+  fileMatch: ['(^|/)\\.circleci/.+\\.ya?ml$'],
 };
 
 export const categories: Category[] = ['ci'];