diff --git a/lib/modules/datasource/repology/readme.md b/lib/modules/datasource/repology/readme.md
index 787585515704bd657cdda7992e987ce4c37751ca..0f04a81c919e0ff80cdfe36e2b8ccec670108e2f 100644
--- a/lib/modules/datasource/repology/readme.md
+++ b/lib/modules/datasource/repology/readme.md
@@ -33,7 +33,7 @@ First you would set a custom manager in your `renovate.json` file for `Dockerfil
 
 Then you would put comments in your Dockerfile, to tell Renovate where to find the updates:
 
-```docker
+```dockerfile
 FROM alpine:3.12.0@sha256:a15790640a6690aa1730c38cf0a440e2aa44aaca9b0e8931a9f2b0d7cc90fd65
 
 # renovate: datasource=repology depName=alpine_3_12/gcc versioning=loose