diff --git a/updater_sample/src/com/example/android/systemupdatersample/services/PrepareStreamingService.java b/updater_sample/src/com/example/android/systemupdatersample/services/PrepareStreamingService.java
index 222bb0a..ac6e223 100644
--- a/updater_sample/src/com/example/android/systemupdatersample/services/PrepareStreamingService.java
+++ b/updater_sample/src/com/example/android/systemupdatersample/services/PrepareStreamingService.java
@@ -116,6 +116,8 @@
                 PackageFiles.PAYLOAD_PROPERTIES_FILE_NAME
             );
 
+    private final PayloadSpecs mPayloadSpecs = new PayloadSpecs();
+
     @Override
     protected void onHandleIntent(Intent intent) {
         Log.d(TAG, "On handle intent is called");
@@ -137,7 +139,7 @@
      * 3. Checks OTA package compatibility with the device.
      * 4. Constructs {@link PayloadSpec} for streaming update.
      */
-    private static PayloadSpec execute(UpdateConfig config)
+    private PayloadSpec execute(UpdateConfig config)
             throws IOException, PreparationFailedException {
 
         downloadPreStreamingFiles(config, OTA_PACKAGE_DIR);
@@ -164,7 +166,7 @@
             }
         }
 
-        return PayloadSpecs.forStreaming(config.getUrl(),
+        return mPayloadSpecs.forStreaming(config.getUrl(),
                 payloadBinary.get().getOffset(),
                 payloadBinary.get().getSize(),
                 Paths.get(OTA_PACKAGE_DIR, PAYLOAD_PROPERTIES_FILE_NAME).toFile());
@@ -176,7 +178,7 @@
      * in directory {@code dir}.
      * @throws IOException when can't download a file
      */
-    private static void downloadPreStreamingFiles(UpdateConfig config, String dir)
+    private void downloadPreStreamingFiles(UpdateConfig config, String dir)
             throws IOException {
         Log.d(TAG, "Deleting existing files from " + dir);
         for (String file : PRE_STREAMING_FILES_SET) {
@@ -200,7 +202,7 @@
      * @param file physical location of {@link PackageFiles#COMPATIBILITY_ZIP_FILE_NAME}
      * @return true if OTA package is compatible with this device
      */
-    private static boolean verifyPackageCompatibility(File file) {
+    private boolean verifyPackageCompatibility(File file) {
         try {
             return RecoverySystem.verifyPackageCompatibility(file);
         } catch (IOException e) {
diff --git a/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java b/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java
index c5a7f95..9bab131 100644
--- a/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java
+++ b/updater_sample/src/com/example/android/systemupdatersample/ui/MainActivity.java
@@ -77,6 +77,7 @@
             new AtomicInteger(UpdateEngine.UpdateStatusConstants.IDLE);
     private PayloadSpec mLastPayloadSpec;
     private AtomicBoolean mManualSwitchSlotRequired = new AtomicBoolean(true);
+    private final PayloadSpecs mPayloadSpecs = new PayloadSpecs();
 
     /**
      * Listen to {@code update_engine} events.
@@ -338,7 +339,7 @@
         if (config.getInstallType() == UpdateConfig.AB_INSTALL_TYPE_NON_STREAMING) {
             PayloadSpec payload;
             try {
-                payload = PayloadSpecs.forNonStreaming(config.getUpdatePackageFile());
+                payload = mPayloadSpecs.forNonStreaming(config.getUpdatePackageFile());
             } catch (IOException e) {
                 Log.e(TAG, "Error creating payload spec", e);
                 Toast.makeText(this, "Error creating payload spec", Toast.LENGTH_LONG)
diff --git a/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java b/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java
index 4db448a..b98b97c 100644
--- a/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java
+++ b/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java
@@ -43,7 +43,7 @@
      * zip file. So we enumerate the entries to identify the offset of the payload file.
      * http://developer.android.com/reference/java/util/zip/ZipFile.html#entries()
      */
-    public static PayloadSpec forNonStreaming(File packageFile) throws IOException {
+    public PayloadSpec forNonStreaming(File packageFile) throws IOException {
         boolean payloadFound = false;
         long payloadOffset = 0;
         long payloadSize = 0;
@@ -100,7 +100,7 @@
     /**
      * Creates a {@link PayloadSpec} for streaming update.
      */
-    public static PayloadSpec forStreaming(String updateUrl,
+    public PayloadSpec forStreaming(String updateUrl,
                                            long offset,
                                            long size,
                                            File propertiesFile) throws IOException {
@@ -115,7 +115,7 @@
     /**
      * Converts an {@link PayloadSpec} to a string.
      */
-    public static String toString(PayloadSpec payloadSpec) {
+    public String specToString(PayloadSpec payloadSpec) {
         return "<PayloadSpec url=" + payloadSpec.getUrl()
                 + ", offset=" + payloadSpec.getOffset()
                 + ", size=" + payloadSpec.getSize()
@@ -124,6 +124,4 @@
                 + ">";
     }
 
-    private PayloadSpecs() {}
-
 }
diff --git a/updater_sample/tests/src/com/example/android/systemupdatersample/util/PayloadSpecsTest.java b/updater_sample/tests/src/com/example/android/systemupdatersample/util/PayloadSpecsTest.java
index d9e5465..3ba84c1 100644
--- a/updater_sample/tests/src/com/example/android/systemupdatersample/util/PayloadSpecsTest.java
+++ b/updater_sample/tests/src/com/example/android/systemupdatersample/util/PayloadSpecsTest.java
@@ -55,6 +55,8 @@
     private Context mTargetContext;
     private Context mTestContext;
 
+    private PayloadSpecs mPayloadSpecs;
+
     @Rule
     public final ExpectedException thrown = ExpectedException.none();
 
@@ -64,6 +66,7 @@
         mTestContext = InstrumentationRegistry.getContext();
 
         mTestDir = mTargetContext.getFilesDir();
+        mPayloadSpecs = new PayloadSpecs();
     }
 
     @Test
@@ -75,7 +78,7 @@
         java.nio.file.Files.deleteIfExists(packageFile.toPath());
         java.nio.file.Files.copy(mTestContext.getResources().openRawResource(R.raw.ota_002_package),
                 packageFile.toPath());
-        PayloadSpec spec = PayloadSpecs.forNonStreaming(packageFile);
+        PayloadSpec spec = mPayloadSpecs.forNonStreaming(packageFile);
 
         assertEquals("correct url", "file://" + packageFile.getAbsolutePath(), spec.getUrl());
         assertEquals("correct payload offset",
@@ -90,7 +93,7 @@
     @Test
     public void forNonStreaming_IOException() throws Exception {
         thrown.expect(IOException.class);
-        PayloadSpecs.forNonStreaming(new File("/fake/news.zip"));
+        mPayloadSpecs.forNonStreaming(new File("/fake/news.zip"));
     }
 
     @Test
@@ -100,7 +103,7 @@
         long size = 200;
         File propertiesFile = createMockPropertiesFile();
 
-        PayloadSpec spec = PayloadSpecs.forStreaming(url, offset, size, propertiesFile);
+        PayloadSpec spec = mPayloadSpecs.forStreaming(url, offset, size, propertiesFile);
         assertEquals("same url", url, spec.getUrl());
         assertEquals("same offset", offset, spec.getOffset());
         assertEquals("same size", size, spec.getSize());