diff --git a/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFake.java b/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFake.java
index 260ff2dafeedd..33ece00849063 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFake.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFake.java
@@ -70,9 +70,7 @@ public class DeviceConfigProxyFake extends DeviceConfigProxy {
 
         for (Pair<Executor, OnPropertiesChangedListener> listener : mListeners) {
             Properties.Builder propBuilder = new Properties.Builder(namespace);
-            for (String key : mProperties.get(namespace).keySet()) {
-                propBuilder.setString(key, mProperties.get(namespace).get(key));
-            }
+            propBuilder.setString(name, value);
             listener.first.execute(() -> listener.second.onPropertiesChanged(propBuilder.build()));
         }
         return true;
diff --git a/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFakeTest.java b/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFakeTest.java
new file mode 100644
index 0000000000000..64e89579393ec
--- /dev/null
+++ b/packages/SystemUI/tests/src/com/android/systemui/util/DeviceConfigProxyFakeTest.java
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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 com.android.systemui.util;
+
+import static android.provider.DeviceConfig.Properties;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.provider.DeviceConfig.OnPropertiesChangedListener;
+
+import androidx.annotation.NonNull;
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import com.android.systemui.SysuiTestCase;
+import com.android.systemui.util.concurrency.FakeExecutor;
+import com.android.systemui.util.time.FakeSystemClock;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class DeviceConfigProxyFakeTest extends SysuiTestCase {
+    private static final String NAMESPACE = "foobar";
+
+    private FakeExecutor mFakeExecutor = new FakeExecutor(new FakeSystemClock());
+
+    private DeviceConfigProxyFake mDeviceConfigProxyFake;
+
+    @Before
+    public void setup() {
+        mDeviceConfigProxyFake = new DeviceConfigProxyFake();
+    }
+
+    @Test
+    public void testOnPropertiesChanged() {
+        TestableListener onPropertiesChangedListener = new TestableListener();
+        String key = "foo";
+        String value = "bar";
+
+        mDeviceConfigProxyFake.addOnPropertiesChangedListener(
+                NAMESPACE, mFakeExecutor, onPropertiesChangedListener);
+
+        mDeviceConfigProxyFake.setProperty(NAMESPACE, key, value, false);
+        mFakeExecutor.runAllReady();
+        assertThat(onPropertiesChangedListener.mProperties).isNotNull();
+        assertThat(onPropertiesChangedListener.mProperties.getKeyset().size()).isEqualTo(1);
+        assertThat(onPropertiesChangedListener.mProperties.getString(key, "")).isEqualTo(value);
+    }
+
+    @Test
+    public void testOnMultiplePropertiesChanged() {
+        TestableListener onPropertiesChangedListener = new TestableListener();
+        String keyA = "foo";
+        String valueA = "bar";
+        String keyB = "bada";
+        String valueB = "boom";
+
+        mDeviceConfigProxyFake.addOnPropertiesChangedListener(
+                NAMESPACE, mFakeExecutor, onPropertiesChangedListener);
+        mDeviceConfigProxyFake.setProperty(NAMESPACE, keyA, valueA, false);
+        mFakeExecutor.runAllReady();
+        assertThat(onPropertiesChangedListener.mProperties).isNotNull();
+        assertThat(onPropertiesChangedListener.mProperties.getKeyset().size()).isEqualTo(1);
+        assertThat(onPropertiesChangedListener.mProperties.getString(keyA, "")).isEqualTo(valueA);
+
+        mDeviceConfigProxyFake.setProperty(NAMESPACE, keyB, valueB, false);
+        mFakeExecutor.runAllReady();
+        assertThat(onPropertiesChangedListener.mProperties).isNotNull();
+        assertThat(onPropertiesChangedListener.mProperties.getKeyset().size()).isEqualTo(1);
+        assertThat(onPropertiesChangedListener.mProperties.getString(keyB, "")).isEqualTo(valueB);
+    }
+
+    private static class TestableListener implements OnPropertiesChangedListener {
+        Properties mProperties;
+
+        TestableListener() {
+        }
+        @Override
+        public void onPropertiesChanged(@NonNull Properties properties) {
+            mProperties = properties;
+        }
+    }
+}