diff --git a/controllers/kustomization_generator_test.go b/controllers/kustomization_generator_test.go
index da73ffb..e40f1e8 100644
--- a/controllers/kustomization_generator_test.go
+++ b/controllers/kustomization_generator_test.go
@@ -50,3 +50,10 @@ func Test_secureBuildKustomization_panic(t *testing.T) {
 		g.Expect(err).To(HaveOccurred())
 	})
 }
+
+func Test_secureBuildKustomization_rel_basedir(t *testing.T) {
+	g := NewWithT(t)
+
+	_, err := secureBuildKustomization("testdata/relbase", "testdata/relbase/clusters/staging/flux-system", false)
+	g.Expect(err).ToNot(HaveOccurred())
+}
diff --git a/controllers/testdata/relbase/clusters/base/configmap.yaml b/controllers/testdata/relbase/clusters/base/configmap.yaml
new file mode 100644
index 0000000..7cb8953
--- /dev/null
+++ b/controllers/testdata/relbase/clusters/base/configmap.yaml
@@ -0,0 +1,8 @@
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: cm
+  namespace: foo
+data:
+  key: value
diff --git a/controllers/testdata/relbase/clusters/base/kustomization.yaml b/controllers/testdata/relbase/clusters/base/kustomization.yaml
new file mode 100644
index 0000000..bbfab0e
--- /dev/null
+++ b/controllers/testdata/relbase/clusters/base/kustomization.yaml
@@ -0,0 +1,5 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - configmap.yaml
diff --git a/controllers/testdata/relbase/clusters/patches.yaml b/controllers/testdata/relbase/clusters/patches.yaml
new file mode 100644
index 0000000..6ae928d
--- /dev/null
+++ b/controllers/testdata/relbase/clusters/patches.yaml
@@ -0,0 +1,8 @@
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: secret
+  namespace: foo
+stringData:
+  bar: foo
diff --git a/controllers/testdata/relbase/clusters/staging/flux-system/kustomization.yaml b/controllers/testdata/relbase/clusters/staging/flux-system/kustomization.yaml
new file mode 100644
index 0000000..a9cbd7e
--- /dev/null
+++ b/controllers/testdata/relbase/clusters/staging/flux-system/kustomization.yaml
@@ -0,0 +1,8 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - secret.yaml
+  - ../../base
+patchesStrategicMerge:
+  - ../../patches.yaml
diff --git a/controllers/testdata/relbase/clusters/staging/flux-system/secret.yaml b/controllers/testdata/relbase/clusters/staging/flux-system/secret.yaml
new file mode 100644
index 0000000..f0fa717
--- /dev/null
+++ b/controllers/testdata/relbase/clusters/staging/flux-system/secret.yaml
@@ -0,0 +1,8 @@
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: secret
+  namespace: foo
+stringData:
+  foo: bar