diff --git a/pkg/runner/mutate/clean.go b/pkg/runner/mutate/convert.go
similarity index 73%
rename from pkg/runner/mutate/clean.go
rename to pkg/runner/mutate/convert.go
index 8ffff534f..38e358972 100644
--- a/pkg/runner/mutate/clean.go
+++ b/pkg/runner/mutate/convert.go
@@ -1,13 +1,13 @@
 package mutate
 
-func clean(in any) map[string]any {
+func convert(in any) map[string]any {
 	data, ok := in.(map[any]any)
 	if !ok {
 		return nil
 	}
 	out := map[string]any{}
 	for k, v := range data {
-		if c := clean(v); c != nil {
+		if c := convert(v); c != nil {
 			out[k.(string)] = c
 		} else {
 			out[k.(string)] = v
diff --git a/pkg/runner/mutate/convert_test.go b/pkg/runner/mutate/convert_test.go
new file mode 100644
index 000000000..a2804fd84
--- /dev/null
+++ b/pkg/runner/mutate/convert_test.go
@@ -0,0 +1,35 @@
+package mutate
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_convert(t *testing.T) {
+	tests := []struct {
+		name string
+		in   any
+		out  map[string]any
+	}{{
+		name: "nil",
+	}, {
+		name: "int",
+		in:   42,
+		out:  nil,
+	}, {
+		name: "ok",
+		in: map[any]any{
+			"foo": "bar",
+		},
+		out: map[string]any{
+			"foo": "bar",
+		},
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := convert(tt.in)
+			assert.Equal(t, tt.out, got)
+		})
+	}
+}
diff --git a/pkg/runner/mutate/merge.go b/pkg/runner/mutate/merge.go
index af0e149a6..137447e6b 100644
--- a/pkg/runner/mutate/merge.go
+++ b/pkg/runner/mutate/merge.go
@@ -46,7 +46,7 @@ func Merge(ctx context.Context, obj unstructured.Unstructured, bindings binding.
 			if err != nil {
 				return obj, err
 			}
-			obj.SetUnstructuredContent(mapsutils.Merge(obj.UnstructuredContent(), clean(patch)))
+			obj.SetUnstructuredContent(mapsutils.Merge(obj.UnstructuredContent(), convert(patch)))
 		}
 	}
 	return obj, nil
diff --git a/pkg/runner/mutate/merge_test.go b/pkg/runner/mutate/merge_test.go
new file mode 100644
index 000000000..6e2199756
--- /dev/null
+++ b/pkg/runner/mutate/merge_test.go
@@ -0,0 +1,120 @@
+package mutate
+
+import (
+	"context"
+	"testing"
+
+	"github.com/kyverno/chainsaw/pkg/apis/v1alpha1"
+	"github.com/stretchr/testify/assert"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+)
+
+func TestMerge(t *testing.T) {
+	in := unstructured.Unstructured{
+		Object: map[string]any{
+			"foo": "bar",
+		},
+	}
+	tests := []struct {
+		name      string
+		in        unstructured.Unstructured
+		out       unstructured.Unstructured
+		modifiers []v1alpha1.Modifier
+		wantErr   bool
+	}{{
+		name: "nil",
+		in:   in,
+		out:  in,
+	}, {
+		name:      "empty",
+		in:        in,
+		modifiers: []v1alpha1.Modifier{},
+		out:       in,
+	}, {
+		name: "annotate",
+		in:   in,
+		modifiers: []v1alpha1.Modifier{{
+			Annotate: &v1alpha1.Any{
+				Value: map[string]any{
+					"foo": "bar",
+				},
+			},
+		}},
+		out: unstructured.Unstructured{
+			Object: map[string]any{
+				"foo": "bar",
+				"metadata": map[string]any{
+					"annotations": map[string]any{
+						"foo": "bar",
+					},
+				},
+			},
+		},
+	}, {
+		name: "label",
+		in:   in,
+		modifiers: []v1alpha1.Modifier{{
+			Label: &v1alpha1.Any{
+				Value: map[string]any{
+					"foo": "bar",
+				},
+			},
+		}},
+		out: unstructured.Unstructured{
+			Object: map[string]any{
+				"foo": "bar",
+				"metadata": map[string]any{
+					"labels": map[string]any{
+						"foo": "bar",
+					},
+				},
+			},
+		},
+	}, {
+		name: "merge",
+		in:   in,
+		modifiers: []v1alpha1.Modifier{{
+			Merge: &v1alpha1.Any{
+				Value: map[string]any{
+					"foo": "baz",
+				},
+			},
+		}},
+		out: unstructured.Unstructured{
+			Object: map[string]any{
+				"foo": "baz",
+			},
+		},
+	}, {
+		name: "merge",
+		in:   in,
+		modifiers: []v1alpha1.Modifier{{
+			Match: &v1alpha1.Any{
+				Value: map[string]any{
+					"foo": "baz",
+				},
+			},
+			Merge: &v1alpha1.Any{
+				Value: map[string]any{
+					"foo": "bar",
+				},
+			},
+		}},
+		out: unstructured.Unstructured{
+			Object: map[string]any{
+				"foo": "bar",
+			},
+		},
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := Merge(context.TODO(), tt.in, nil, tt.modifiers...)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.out, got)
+			}
+		})
+	}
+}