diff --git a/MyTracks/src/com/google/android/apps/mytracks/io/TempFileCleaner.java b/MyTracks/src/com/google/android/apps/mytracks/io/TempFileCleaner.java
index eb7f9b2ea..867f706d3 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/io/TempFileCleaner.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/io/TempFileCleaner.java
@@ -25,7 +25,14 @@ import java.io.File;
  */
 public class TempFileCleaner {
   
+  private long currentTimeMillis;
+
   public TempFileCleaner() {
+    currentTimeMillis = System.currentTimeMillis();
+  }
+
+  public TempFileCleaner(long time) {
+    currentTimeMillis = time;
   }
   
   public void clean() {
@@ -47,17 +54,20 @@ public class TempFileCleaner {
             + "tmp"));
   }
 
-  private void cleanTmpDirectory(File dir) {
+  // VisibleForTesting
+  protected int cleanTmpDirectory(File dir) {
     if (!dir.exists()) {
-      return;
+      return 0;
     }
     File[] list = dir.listFiles();
-    long now = System.currentTimeMillis();
-    long oldest = now - 1000 * 3600;
+    int count = 0;
+    long oldest = currentTimeMillis - 1000 * 3600;
     for (File f : list) {
       if (f.lastModified() < oldest) {
         f.delete();
+        count++;
       }
     }
+    return count;
   }
 }
diff --git a/MyTracksTest/src/com/google/android/apps/mytracks/io/TempFileCleanerTest.java b/MyTracksTest/src/com/google/android/apps/mytracks/io/TempFileCleanerTest.java
new file mode 100644
index 000000000..93cfdf11d
--- /dev/null
+++ b/MyTracksTest/src/com/google/android/apps/mytracks/io/TempFileCleanerTest.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2010 Google 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 com.google.android.apps.mytracks.io;
+
+import static com.google.android.testing.mocking.AndroidMock.expect;
+import com.google.android.testing.mocking.AndroidMock;
+import com.google.android.testing.mocking.UsesMocks;
+
+import android.test.AndroidTestCase;
+
+import java.io.File;
+
+/**
+ * @author Sandor Dornbush
+ */
+public class TempFileCleanerTest extends AndroidTestCase {
+  
+  @UsesMocks({
+    File.class,
+  })
+
+  public void test_noDir() {
+    File dir = AndroidMock.createMock(File.class, "/no_file");
+    TempFileCleaner cleaner = new TempFileCleaner();
+    expect(dir.exists()).andStubReturn(false);
+    AndroidMock.replay(dir);
+    assertEquals(0, cleaner.cleanTmpDirectory(dir));
+    AndroidMock.verify(dir);
+  }
+
+  public void test_emptyDir() {
+    File dir = AndroidMock.createMock(File.class, "/no_file");
+    TempFileCleaner cleaner = new TempFileCleaner();
+    expect(dir.exists()).andStubReturn(true);
+    expect(dir.listFiles()).andStubReturn(new File[0]);
+    AndroidMock.replay(dir);
+    assertEquals(0, cleaner.cleanTmpDirectory(dir));
+    AndroidMock.verify(dir);
+  }
+
+  public void test_newFile() {
+    File dir = AndroidMock.createMock(File.class, "/no_file");
+    long now = 100000000;
+    TempFileCleaner cleaner = new TempFileCleaner(now);
+    expect(dir.exists()).andStubReturn(true);
+    File file = AndroidMock.createMock(File.class, "/no_file/foo");
+    expect(file.lastModified()).andStubReturn(now);
+    File[] list = { file };
+    expect(dir.listFiles()).andStubReturn(list);
+    
+    AndroidMock.replay(dir, file);
+    assertEquals(0, cleaner.cleanTmpDirectory(dir));
+    AndroidMock.verify(dir, file);
+  }
+
+  public void test_oldFile() {
+    File dir = AndroidMock.createMock(File.class, "/no_file");
+    long now = 100000000;
+    TempFileCleaner cleaner = new TempFileCleaner(now);
+    expect(dir.exists()).andStubReturn(true);
+    File file = AndroidMock.createMock(File.class, "/no_file/foo");
+    expect(file.lastModified()).andStubReturn(now - 3600001);
+    expect(file.delete()).andStubReturn(true);
+    File[] list = { file };
+    expect(dir.listFiles()).andStubReturn(list);
+    
+    AndroidMock.replay(dir, file);
+    assertEquals(1, cleaner.cleanTmpDirectory(dir));
+    AndroidMock.verify(dir, file);
+  }
+}