diff --git a/bulldozer/update.go b/bulldozer/update.go
index 14ef37a0f..49c655322 100644
--- a/bulldozer/update.go
+++ b/bulldozer/update.go
@@ -28,6 +28,10 @@ import (
 func ShouldUpdatePR(ctx context.Context, pullCtx pull.Context, updateConfig UpdateConfig) (bool, error) {
 	logger := zerolog.Ctx(ctx)
 
+	if !updateConfig.Blacklist.Enabled() && !updateConfig.Whitelist.Enabled() {
+		return false, nil
+	}
+
 	if updateConfig.Blacklist.Enabled() {
 		blacklisted, reason, err := IsPRBlacklisted(ctx, pullCtx, updateConfig.Blacklist)
 		if err != nil {
diff --git a/bulldozer/update_test.go b/bulldozer/update_test.go
new file mode 100644
index 000000000..39575fadf
--- /dev/null
+++ b/bulldozer/update_test.go
@@ -0,0 +1,85 @@
+// Copyright 2018 Palantir Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package bulldozer
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/palantir/bulldozer/pull"
+	"github.com/palantir/bulldozer/pull/pulltest"
+)
+
+func TestShouldUpdatePR(t *testing.T) {
+	ctx := context.Background()
+	testMatrix := []struct {
+		blacklistEnabled bool
+		blacklisted      bool
+		whitelistEnabled bool
+		whitelisted      bool
+		expectingUpdate  bool
+	}{
+		{false, false, false, false, false},
+		{false, false, false, true, false},
+		{false, false, true, false, false},
+		{false, false, true, true, true},
+		{false, true, false, false, false},
+		{false, true, false, true, false},
+		{false, true, true, false, false},
+		{false, true, true, true, true},
+		{true, false, false, false, true},
+		{true, false, false, true, true},
+		{true, false, true, false, false},
+		{true, false, true, true, true},
+		{true, true, false, false, false},
+		{true, true, false, true, false},
+		{true, true, true, false, false},
+		{true, true, true, true, false},
+	}
+
+	for ndx, testCase := range testMatrix {
+		pullCtx, updateConfig := generateUpdateTestCase(testCase.blacklistEnabled, testCase.blacklisted, testCase.whitelistEnabled, testCase.whitelisted)
+		updating, err := ShouldUpdatePR(ctx, pullCtx, updateConfig)
+		require.NoError(t, err)
+		msg := fmt.Sprintf("case %d - blacklistEnabled=%t blacklisted=%t whitelistEnabled=%t whitelisted=%t -> doUpdate=%t",
+			ndx, testCase.blacklistEnabled, testCase.blacklisted, testCase.whitelistEnabled, testCase.whitelisted, testCase.expectingUpdate)
+		require.Equal(t, testCase.expectingUpdate, updating, msg)
+	}
+}
+func generateUpdateTestCase(blacklistable bool, blacklisted bool, whitelistable bool, whitelisted bool) (pull.Context, UpdateConfig) {
+	updateConfig := UpdateConfig{}
+	pullCtx := pulltest.MockPullContext{}
+
+	if blacklistable {
+		updateConfig.Blacklist.Labels = append(updateConfig.Blacklist.Labels, "blacklist")
+	}
+
+	if blacklisted {
+		pullCtx.LabelValue = append(pullCtx.LabelValue, "blacklist")
+	}
+
+	if whitelistable {
+		updateConfig.Whitelist.Labels = append(updateConfig.Whitelist.Labels, "whitelist")
+	}
+
+	if whitelisted {
+		pullCtx.LabelValue = append(pullCtx.LabelValue, "whitelist")
+	}
+
+	return &pullCtx, updateConfig
+}