diff --git a/pkg/registry/thirdpartyresourcedata/codec.go b/pkg/registry/thirdpartyresourcedata/codec.go
index 74a8a51a16b..8fedc1027ad 100644
--- a/pkg/registry/thirdpartyresourcedata/codec.go
+++ b/pkg/registry/thirdpartyresourcedata/codec.go
@@ -42,7 +42,8 @@ type thirdPartyResourceDataMapper struct {
 var _ meta.RESTMapper = &thirdPartyResourceDataMapper{}
 
 func (t *thirdPartyResourceDataMapper) isThirdPartyResource(resource string) bool {
-	return resource == strings.ToLower(t.kind)+"s"
+	plural, _ := meta.KindToResource(t.kind, false)
+	return resource == plural
 }
 
 func (t *thirdPartyResourceDataMapper) KindFor(resource string) (unversioned.GroupVersionKind, error) {
diff --git a/pkg/registry/thirdpartyresourcedata/codec_test.go b/pkg/registry/thirdpartyresourcedata/codec_test.go
index a83dad36cbf..62125c1467d 100644
--- a/pkg/registry/thirdpartyresourcedata/codec_test.go
+++ b/pkg/registry/thirdpartyresourcedata/codec_test.go
@@ -181,3 +181,44 @@ func TestCreater(t *testing.T) {
 
 	}
 }
+
+func TestResourceIsValid(t *testing.T) {
+	tests := []struct {
+		kind     string
+		resource string
+		valid    bool
+		name     string
+	}{
+		{
+			kind:     "Foo",
+			resource: "foos",
+			valid:    true,
+			name:     "basic",
+		},
+		{
+			kind:     "Party",
+			resource: "parties",
+			valid:    true,
+			name:     "fun",
+		},
+		{
+			kind:     "bus",
+			resource: "buses",
+			valid:    true,
+			name:     "transport",
+		},
+		{
+			kind:     "Foo",
+			resource: "fooies",
+			name:     "bad",
+		},
+	}
+	for _, test := range tests {
+		mapper := &thirdPartyResourceDataMapper{kind: test.kind}
+		mapper.mapper = api.RESTMapper
+		valid := mapper.ResourceIsValid(test.resource)
+		if valid != test.valid {
+			t.Errorf("expected: %v, saw: %v for %s", test.valid, valid, test.name)
+		}
+	}
+}