diff --git a/cmd/xtcp2/treatments_embedded.go b/cmd/xtcp2/treatments_embedded.go
index 8e9b31901..50a63de9b 100644
--- a/cmd/xtcp2/treatments_embedded.go
+++ b/cmd/xtcp2/treatments_embedded.go
@@ -37,5 +37,11 @@ func startEmbeddedTreatmentAgent(ctx context.Context, path, location string) (*t
 	var wg sync.WaitGroup
 	wg.Add(1)
 	go func() { defer wg.Done(); a.Run(ctx) }()
-	return &treatmentFeeder{stamp: a.Stamp, wake: a.Wake}, func() { wg.Wait(); a.Close() }, nil
+	stop := func() {
+		wg.Wait()
+		if err := a.Close(); err != nil {
+			log.Printf("treatment agent: close: %v", err)
+		}
+	}
+	return &treatmentFeeder{stamp: a.Stamp, wake: a.Wake}, stop, nil
 }
diff --git a/nix/tests/tcp-controller/quality.nix b/nix/tests/tcp-controller/quality.nix
index 946f5995f..67b339c6e 100644
--- a/nix/tests/tcp-controller/quality.nix
+++ b/nix/tests/tcp-controller/quality.nix
@@ -53,7 +53,9 @@ let
         # These fixtures must execute, never silently skip in the focused checks.
         grep -q -- '--- PASS: TestPostgresConcurrentReviewFencesReplicas' "$out/tests.log"
         grep -q -- '--- PASS: TestClickHouseAnalysisCounterDeltas' "$out/tests.log"
-        go test -tags treatment -ldflags=-checklinkname=0 ${if race then "-race -count=3" else "-count=1 -cover"} \
+        go test -tags treatment -ldflags=-checklinkname=0 ${
+          if race then "-race -count=3" else "-count=1 -cover"
+        } \
           -timeout 5m -v -run '^TestTreatment' ./internal/goip/actuate > "$out/routes.log" 2>&1 \
           || { cat "$out/routes.log"; exit 1; }
         ${if race then "" else coverageTable}