diff --git a/extraresources.go b/extraresources.go
index 20b89a7..b898804 100644
--- a/extraresources.go
+++ b/extraresources.go
@@ -48,11 +48,10 @@ func (e *ExtraResourcesRequirement) ToResourceSelector() *fnv1.ResourceSelector
 		out.Match = &fnv1.ResourceSelector_MatchLabels{
 			MatchLabels: &fnv1.MatchLabels{Labels: e.MatchLabels},
 		}
-		return out
-	}
-
-	out.Match = &fnv1.ResourceSelector_MatchName{
-		MatchName: e.MatchName,
+	} else {
+		out.Match = &fnv1.ResourceSelector_MatchName{
+			MatchName: e.MatchName,
+		}
 	}
 
 	if e.Namespace != "" {
diff --git a/extraresources_test.go b/extraresources_test.go
new file mode 100644
index 0000000..ef45fa2
--- /dev/null
+++ b/extraresources_test.go
@@ -0,0 +1,87 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"google.golang.org/protobuf/testing/protocmp"
+
+	fnv1 "github.com/crossplane/function-sdk-go/proto/v1"
+)
+
+func TestExtraResourcesRequirementToResourceSelector(t *testing.T) {
+	ns := "test"
+
+	cases := map[string]struct {
+		reason string
+		e      ExtraResourcesRequirement
+		want   *fnv1.ResourceSelector
+	}{
+		"MatchLabelsWithNamespace": {
+			reason: "Namespace must be set on the selector when MatchLabels is used, not just MatchName.",
+			e: ExtraResourcesRequirement{
+				APIVersion: "example.org/v1",
+				Kind:       "CoolExtraResource",
+				MatchLabels: map[string]string{
+					"cool": "true",
+				},
+				Namespace: ns,
+			},
+			want: &fnv1.ResourceSelector{
+				ApiVersion: "example.org/v1",
+				Kind:       "CoolExtraResource",
+				Match: &fnv1.ResourceSelector_MatchLabels{
+					MatchLabels: &fnv1.MatchLabels{Labels: map[string]string{
+						"cool": "true",
+					}},
+				},
+				Namespace: &ns,
+			},
+		},
+		"MatchLabelsWithoutNamespace": {
+			reason: "Namespace must be left unset when it is empty.",
+			e: ExtraResourcesRequirement{
+				APIVersion: "example.org/v1",
+				Kind:       "CoolExtraResource",
+				MatchLabels: map[string]string{
+					"cool": "true",
+				},
+			},
+			want: &fnv1.ResourceSelector{
+				ApiVersion: "example.org/v1",
+				Kind:       "CoolExtraResource",
+				Match: &fnv1.ResourceSelector_MatchLabels{
+					MatchLabels: &fnv1.MatchLabels{Labels: map[string]string{
+						"cool": "true",
+					}},
+				},
+			},
+		},
+		"MatchNameWithNamespace": {
+			reason: "Namespace must still be set when MatchName is used.",
+			e: ExtraResourcesRequirement{
+				APIVersion: "example.org/v1",
+				Kind:       "CoolExtraResource",
+				MatchName:  "cool-extra-resource",
+				Namespace:  ns,
+			},
+			want: &fnv1.ResourceSelector{
+				ApiVersion: "example.org/v1",
+				Kind:       "CoolExtraResource",
+				Match: &fnv1.ResourceSelector_MatchName{
+					MatchName: "cool-extra-resource",
+				},
+				Namespace: &ns,
+			},
+		},
+	}
+
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			got := tc.e.ToResourceSelector()
+			if diff := cmp.Diff(tc.want, got, protocmp.Transform()); diff != "" {
+				t.Errorf("\n%s\nToResourceSelector(...): -want, +got:\n%s", tc.reason, diff)
+			}
+		})
+	}
+}