diff --git a/lib/modules/manager/dockerfile/index.ts b/lib/modules/manager/dockerfile/index.ts
index 0f6e68b7f61ca3e62c97ddb351b58a6afb395911..0e011c1730d1d462c24fd5f0b40efe06e8e24109 100644
--- a/lib/modules/manager/dockerfile/index.ts
+++ b/lib/modules/manager/dockerfile/index.ts
@@ -7,7 +7,10 @@ export const language: ProgrammingLanguage = 'docker';
 export { extractPackageFile };
 
 export const defaultConfig = {
-  fileMatch: ['(^|/|\\.)Dockerfile$', '(^|/)Dockerfile[^/]*$'],
+  fileMatch: [
+    '(^|/|\\.)(Docker|Container)file$',
+    '(^|/)(Docker|Container)file[^/]*$',
+  ],
 };
 
 export const supportedDatasources = [DockerDatasource.id];
diff --git a/lib/modules/manager/dockerfile/readme.md b/lib/modules/manager/dockerfile/readme.md
index 24a3d124c558b1bca497d109caf5a2d3f7b203d7..f2158d91b4679becd35563d064c5aafc2d4892a5 100644
--- a/lib/modules/manager/dockerfile/readme.md
+++ b/lib/modules/manager/dockerfile/readme.md
@@ -1,10 +1,10 @@
-Extracts all Docker images in a `Dockerfile`.
+Extracts image references in a `Dockerfile` and/or `Containerfile`.
 
 Renovate's managers does not understand versioning, that's up to Renovate's versioning modules.
-The default Docker versioning for Docker datasources treats suffixes as "compatibility", for example: `-alpine`.
-Many Docker images are _not_ SemVer compliant because they use such suffixes in their tags.
+The default `docker` versioning for container image datasources treats suffixes as "compatibility", for example: `-alpine`.
+Many container images are _not_ SemVer compliant because they use such suffixes in their tags.
 
-If Renovate does not update your Dockerfile images correctly, you may need to tell Renovate what versioning it should use.
+If Renovate does not update your container images correctly, you may need to tell Renovate what versioning it should use.
 For example, if you know that an image follows SemVer, you can tell Renovate to use `"semver"` versioning for that image:
 
 ```json
diff --git a/lib/workers/repository/extract/extract-fingerprint-config.spec.ts b/lib/workers/repository/extract/extract-fingerprint-config.spec.ts
index e18da13569c136193067bac5b80aa39d264a6113..76977db75521837a3034eff85ea362d45575f4ef 100644
--- a/lib/workers/repository/extract/extract-fingerprint-config.spec.ts
+++ b/lib/workers/repository/extract/extract-fingerprint-config.spec.ts
@@ -99,7 +99,10 @@ describe('workers/repository/extract/extract-fingerprint-config', () => {
     ).toEqual({
       enabled: true,
       fileList: [],
-      fileMatch: ['(^|/|\\.)Dockerfile$', '(^|/)Dockerfile[^/]*$'],
+      fileMatch: [
+        '(^|/|\\.)(Docker|Container)file$',
+        '(^|/)(Docker|Container)file[^/]*$',
+      ],
       ignorePaths: ['**/node_modules/**', '**/bower_components/**'],
       includePaths: [],
       manager: 'dockerfile',