diff --git a/internal/tools/template/helm_passthrough_test.go b/internal/tools/template/helm_passthrough_test.go
new file mode 100644
index 0000000..ec28935
--- /dev/null
+++ b/internal/tools/template/helm_passthrough_test.go
@@ -0,0 +1,21 @@
+package template
+
+import "testing"
+
+func TestHelmChartPassesThroughVerbatim(t *testing.T) {
+	// The file that failed on krateo-057: publish-sock-shop-003 / microservices.yaml
+	//   "create failed: unable to copy files: template: template:61: function \"toYaml\" not defined"
+	body := `resources:
+  {{- toYaml .Values.resources | nindent 4 }}
+{{- include "chart.labels" . }}
+{{/* a helpers.tpl header */}}
+value: {{ .Values.name }}
+`
+	got, err := Template(body).Render(map[string]any{})
+	if err != nil {
+		t.Fatalf("a Helm chart must commit verbatim, got render error: %v", err)
+	}
+	if string(got) != body {
+		t.Errorf("content was altered.\n--- want ---\n%s\n--- got ---\n%s", body, got)
+	}
+}