diff --git a/services/data-manager/Dockerfile b/services/data-manager/Dockerfile
index a8696dee..3b274cce 100644
--- a/services/data-manager/Dockerfile
+++ b/services/data-manager/Dockerfile
@@ -17,7 +17,7 @@
 # The GitHub Actions workflow at .github/workflows/docker.yml builds this
 # image with `context: .` for the same reason.
 
-FROM docker.io/golang:1.26@sha256:2005724102f45917a63e9d092fc0e4ea56ea575048ce147caad5f5f61502c365 AS build-gtfsclean
+FROM docker.io/golang:1.27rc2@sha256:d901fb8d9f6754d898c85bb9331ad76dbe039103b01cf0c068bb31f92e019788 AS build-gtfsclean
 # Pin gtfsclean to a commit (the project only publishes rolling snapshot-N tags)
 # instead of @latest so the build is reproducible and can't silently pull new code.
 RUN GOPROXY=direct GOBIN=/usr/local/bin/ go install github.com/public-transport/gtfsclean@bb3ea74f66ef9bc07dc1bd038c3f653e10f0ade0 # snapshot-5