diff --git a/Dockerfile b/Dockerfile
index a8cfb8c..f2f9d83 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,8 +24,8 @@ RUN --mount=type=cache,target=/root/.cache/go-build \
 # image ships and the alpine one does not. -count=1 because the mounted
 # cache also holds test results, which go test would otherwise replay.
 # -short skips the live RIS Live feed test, so the suite needs no network.
-# golang:1.24-bookworm, 2026-09-21
-FROM golang@sha256:1a6d4452c65dea36aac2e2d606b01b4a029ec90cc1ae53890540ce6173ea77ac AS test
+# golang:1.27.2-bookworm, 2026-10-19
+FROM golang@sha256:5cf287a799e6b94384bad13d16b14904c531f51ba65792237e122ce42b392f61 AS test
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
@@ -39,8 +39,8 @@ RUN --mount=type=cache,target=/root/.cache/go-build \
 # Build stage. Nothing is wanted from either phase above; the copies
 # are what make BuildKit build them first, so nothing after them can
 # run unless lint and test passed.
-# golang:1.24-bookworm, 2026-09-21
-FROM golang@sha256:1a6d4452c65dea36aac2e2d606b01b4a029ec90cc1ae53890540ce6173ea77ac AS builder
+# golang:1.27.2-bookworm, 2026-10-19
+FROM golang@sha256:5cf287a799e6b94384bad13d16b14904c531f51ba65792237e122ce42b392f61 AS builder
 
 # Install build dependencies (zstd for archive, gcc for CGO/sqlite3)
 RUN apt-get update && apt-get install -y --no-install-recommends \
diff --git a/go.mod b/go.mod
index 4d318d3..10d57f5 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module git.eeqj.de/sneak/routewatch
 
-go 1.24.4
+go 1.27.1
 
 require (
 	github.com/dustin/go-humanize v1.0.1
diff --git a/internal/database/database_internal_test.go b/internal/database/database_internal_test.go
index 92768c9..7a48559 100644
--- a/internal/database/database_internal_test.go
+++ b/internal/database/database_internal_test.go
@@ -564,11 +564,8 @@ func TestBatchWriteDuringCheckpoint(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 
 	var wg sync.WaitGroup
-	wg.Add(1)
-
-	go func() {
-		defer wg.Done()
 
+	wg.Go(func() {
 		for {
 			select {
 			case <-ctx.Done():
@@ -577,7 +574,7 @@ func TestBatchWriteDuringCheckpoint(t *testing.T) {
 				_ = db.Checkpoint(ctx) // errors are the checkpoint's own to absorb
 			}
 		}
-	}()
+	})
 
 	ts := time.Now().UTC()
 	for i := range contentionIterations {