diff --git a/instrumentation/src/com/android/test/runner/MultiDexTestRunner.java b/instrumentation/src/com/android/test/runner/MultiDexTestRunner.java
index 3de3632..d6931d1 100644
--- a/instrumentation/src/com/android/test/runner/MultiDexTestRunner.java
+++ b/instrumentation/src/com/android/test/runner/MultiDexTestRunner.java
@@ -32,7 +32,7 @@
 
     @Override
     public void onCreate(Bundle arguments) {
-        MultiDex.install(getTargetContext());
+        MultiDex.installInstrumentation(getContext(), getTargetContext());
         super.onCreate(arguments);
     }
 
diff --git a/library/src/android/support/multidex/MultiDex.java b/library/src/android/support/multidex/MultiDex.java
index d35da96..ab7f668 100644
--- a/library/src/android/support/multidex/MultiDex.java
+++ b/library/src/android/support/multidex/MultiDex.java
@@ -17,6 +17,7 @@
 package android.support.multidex;
 
 import android.app.Application;
+import android.app.Instrumentation;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.os.Build;
@@ -70,7 +71,9 @@
 
     private static final int VM_WITH_MULTIDEX_VERSION_MINOR = 1;
 
-    private static final Set<String> installedApk = new HashSet<String>();
+    private static final String NO_KEY_PREFIX = "";
+
+    private static final Set<File> installedApk = new HashSet<File>();
 
     private static final boolean IS_VM_MULTIDEX_CAPABLE =
             isVMMultidexCapable(System.getProperty("java.vm.version"));
@@ -88,83 +91,164 @@
      *         extension.
      */
     public static void install(Context context) {
-        Log.i(TAG, "install");
+        Log.i(TAG, "Installing application");
         if (IS_VM_MULTIDEX_CAPABLE) {
             Log.i(TAG, "VM has multidex support, MultiDex support library is disabled.");
             return;
         }
 
         if (Build.VERSION.SDK_INT < MIN_SDK_VERSION) {
-            throw new RuntimeException("Multi dex installation failed. SDK " + Build.VERSION.SDK_INT
+            throw new RuntimeException("MultiDex installation failed. SDK " + Build.VERSION.SDK_INT
                     + " is unsupported. Min SDK version is " + MIN_SDK_VERSION + ".");
         }
 
         try {
             ApplicationInfo applicationInfo = getApplicationInfo(context);
             if (applicationInfo == null) {
-                // Looks like running on a test Context, so just return without patching.
+              Log.i(TAG, "No ApplicationInfo available, i.e. running on a test Context:"
+                  + " MultiDex support library is disabled.");
+              return;
+            }
+
+            doInstallation(context,
+                    new File(applicationInfo.sourceDir),
+                    new File(applicationInfo.dataDir),
+                    CODE_CACHE_SECONDARY_FOLDER_NAME,
+                    NO_KEY_PREFIX);
+
+        } catch (Exception e) {
+            Log.e(TAG, "MultiDex installation failure", e);
+            throw new RuntimeException("MultiDex installation failed (" + e.getMessage() + ").");
+        }
+        Log.i(TAG, "install done");
+    }
+
+    /**
+     * Patches the instrumentation context class loader by appending extra dex files
+     * loaded from the instrumentation apk and the application apk. This method should be called in
+     * the onCreate of your {@link Instrumentation}, see
+     * {@link com.android.test.runner.MultiDexTestRunner} for an example.
+     *
+     * @param instrumentationContext instrumentation context.
+     * @param targetContext target application context.
+     * @throws RuntimeException if an error occurred preventing the classloader
+     *         extension.
+     */
+    public static void installInstrumentation(Context instrumentationContext,
+            Context targetContext) {
+        Log.i(TAG, "Installing instrumentation");
+
+        if (IS_VM_MULTIDEX_CAPABLE) {
+            Log.i(TAG, "VM has multidex support, MultiDex support library is disabled.");
+            return;
+        }
+
+        if (Build.VERSION.SDK_INT < MIN_SDK_VERSION) {
+            throw new RuntimeException("MultiDex installation failed. SDK " + Build.VERSION.SDK_INT
+                    + " is unsupported. Min SDK version is " + MIN_SDK_VERSION + ".");
+        }
+        try {
+
+            ApplicationInfo instrumentationInfo = getApplicationInfo(instrumentationContext);
+            if (instrumentationInfo == null) {
+                Log.i(TAG, "No ApplicationInfo available for instrumentation, i.e. running on a"
+                    + " test Context: MultiDex support library is disabled.");
                 return;
             }
 
-            synchronized (installedApk) {
-                String apkPath = applicationInfo.sourceDir;
-                if (installedApk.contains(apkPath)) {
-                    return;
-                }
-                installedApk.add(apkPath);
-
-                if (Build.VERSION.SDK_INT > MAX_SUPPORTED_SDK_VERSION) {
-                    Log.w(TAG, "MultiDex is not guaranteed to work in SDK version "
-                            + Build.VERSION.SDK_INT + ": SDK version higher than "
-                            + MAX_SUPPORTED_SDK_VERSION + " should be backed by "
-                            + "runtime with built-in multidex capabilty but it's not the "
-                            + "case here: java.vm.version=\""
-                            + System.getProperty("java.vm.version") + "\"");
-                }
-
-                /* The patched class loader is expected to be a descendant of
-                 * dalvik.system.BaseDexClassLoader. We modify its
-                 * dalvik.system.DexPathList pathList field to append additional DEX
-                 * file entries.
-                 */
-                ClassLoader loader;
-                try {
-                    loader = context.getClassLoader();
-                } catch (RuntimeException e) {
-                    /* Ignore those exceptions so that we don't break tests relying on Context like
-                     * a android.test.mock.MockContext or a android.content.ContextWrapper with a
-                     * null base Context.
-                     */
-                    Log.w(TAG, "Failure while trying to obtain Context class loader. " +
-                            "Must be running in test mode. Skip patching.", e);
-                    return;
-                }
-                if (loader == null) {
-                    // Note, the context class loader is null when running Robolectric tests.
-                    Log.e(TAG,
-                            "Context class loader is null. Must be running in test mode. "
-                            + "Skip patching.");
-                    return;
-                }
-
-                try {
-                  clearOldDexDir(context);
-                } catch (Throwable t) {
-                  Log.w(TAG, "Something went wrong when trying to clear old MultiDex extraction, "
-                      + "continuing without cleaning.", t);
-                }
-
-                File dexDir = getDexDir(context, applicationInfo);
-                List<? extends File> files =
-                    MultiDexExtractor.load(context, applicationInfo, dexDir, false);
-                installSecondaryDexes(loader, dexDir, files);
+            ApplicationInfo applicationInfo = getApplicationInfo(targetContext);
+            if (applicationInfo == null) {
+                Log.i(TAG, "No ApplicationInfo available, i.e. running on a test Context:"
+                    + " MultiDex support library is disabled.");
+                return;
             }
 
+            String instrumentationPrefix = instrumentationContext.getPackageName() + ".";
+
+            File dataDir = new File(applicationInfo.dataDir);
+
+            doInstallation(targetContext,
+                    new File(instrumentationInfo.sourceDir),
+                    dataDir,
+                    instrumentationPrefix + CODE_CACHE_SECONDARY_FOLDER_NAME,
+                    instrumentationPrefix);
+
+            doInstallation(targetContext,
+                    new File(applicationInfo.sourceDir),
+                    dataDir,
+                    CODE_CACHE_SECONDARY_FOLDER_NAME,
+                    NO_KEY_PREFIX);
         } catch (Exception e) {
-            Log.e(TAG, "Multidex installation failure", e);
-            throw new RuntimeException("Multi dex installation failed (" + e.getMessage() + ").");
+            Log.e(TAG, "MultiDex installation failure", e);
+            throw new RuntimeException("MultiDex installation failed (" + e.getMessage() + ").");
         }
-        Log.i(TAG, "install done");
+        Log.i(TAG, "Installation done");
+    }
+
+    /**
+     * @param mainContext context used to get filesDir, to save preference and to get the
+     * classloader to patch.
+     * @param sourceApk Apk file.
+     * @param dataDir data directory to use for code cache simulation.
+     * @param secondaryFolderName name of the folder for storing extractions.
+     * @param prefsKeyPrefix prefix of all stored preference keys.
+     */
+    private static void doInstallation(Context mainContext, File sourceApk, File dataDir,
+            String secondaryFolderName, String prefsKeyPrefix) throws IOException,
+                IllegalArgumentException, IllegalAccessException, NoSuchFieldException,
+                InvocationTargetException, NoSuchMethodException {
+        synchronized (installedApk) {
+            if (installedApk.contains(sourceApk)) {
+                return;
+            }
+            installedApk.add(sourceApk);
+
+            if (Build.VERSION.SDK_INT > MAX_SUPPORTED_SDK_VERSION) {
+                Log.w(TAG, "MultiDex is not guaranteed to work in SDK version "
+                        + Build.VERSION.SDK_INT + ": SDK version higher than "
+                        + MAX_SUPPORTED_SDK_VERSION + " should be backed by "
+                        + "runtime with built-in multidex capabilty but it's not the "
+                        + "case here: java.vm.version=\""
+                        + System.getProperty("java.vm.version") + "\"");
+            }
+
+            /* The patched class loader is expected to be a descendant of
+             * dalvik.system.BaseDexClassLoader. We modify its
+             * dalvik.system.DexPathList pathList field to append additional DEX
+             * file entries.
+             */
+            ClassLoader loader;
+            try {
+                loader = mainContext.getClassLoader();
+            } catch (RuntimeException e) {
+                /* Ignore those exceptions so that we don't break tests relying on Context like
+                 * a android.test.mock.MockContext or a android.content.ContextWrapper with a
+                 * null base Context.
+                 */
+                Log.w(TAG, "Failure while trying to obtain Context class loader. " +
+                        "Must be running in test mode. Skip patching.", e);
+                return;
+            }
+            if (loader == null) {
+                // Note, the context class loader is null when running Robolectric tests.
+                Log.e(TAG,
+                        "Context class loader is null. Must be running in test mode. "
+                        + "Skip patching.");
+                return;
+            }
+
+            try {
+              clearOldDexDir(mainContext);
+            } catch (Throwable t) {
+              Log.w(TAG, "Something went wrong when trying to clear old MultiDex extraction, "
+                  + "continuing without cleaning.", t);
+            }
+
+            File dexDir = getDexDir(mainContext, dataDir, secondaryFolderName);
+            List<? extends File> files =
+                    MultiDexExtractor.load(mainContext, sourceApk, dexDir, prefsKeyPrefix, false);
+            installSecondaryDexes(loader, dexDir, files);
+        }
     }
 
     private static ApplicationInfo getApplicationInfo(Context context) {
@@ -335,9 +419,9 @@
         }
     }
 
-    private static File getDexDir(Context context, ApplicationInfo applicationInfo)
+    private static File getDexDir(Context context, File dataDir, String secondaryFolderName)
             throws IOException {
-        File cache = new File(applicationInfo.dataDir, CODE_CACHE_NAME);
+        File cache = new File(dataDir, CODE_CACHE_NAME);
         try {
             mkdirChecked(cache);
         } catch (IOException e) {
@@ -348,7 +432,7 @@
             cache = new File(context.getFilesDir(), CODE_CACHE_NAME);
             mkdirChecked(cache);
         }
-        File dexDir = new File(cache, CODE_CACHE_SECONDARY_FOLDER_NAME);
+        File dexDir = new File(cache, secondaryFolderName);
         mkdirChecked(dexDir);
         return dexDir;
     }
diff --git a/library/src/android/support/multidex/MultiDexExtractor.java b/library/src/android/support/multidex/MultiDexExtractor.java
index 2d7402a..39b6bf7 100644
--- a/library/src/android/support/multidex/MultiDexExtractor.java
+++ b/library/src/android/support/multidex/MultiDexExtractor.java
@@ -18,7 +18,6 @@
 
 import android.content.Context;
 import android.content.SharedPreferences;
-import android.content.pm.ApplicationInfo;
 import android.os.Build;
 import android.util.Log;
 import java.io.BufferedOutputStream;
@@ -93,10 +92,11 @@
      * @throws IOException if encounters a problem while reading or writing
      *         secondary dex files
      */
-    static List<? extends File> load(Context context, ApplicationInfo applicationInfo, File dexDir,
+    static List<? extends File> load(Context context, File sourceApk, File dexDir,
+            String prefsKeyPrefix,
             boolean forceReload) throws IOException {
-        Log.i(TAG, "MultiDexExtractor.load(" + applicationInfo.sourceDir + ", " + forceReload + ")");
-        final File sourceApk = new File(applicationInfo.sourceDir);
+        Log.i(TAG, "MultiDexExtractor.load(" + sourceApk.getPath() + ", " + forceReload + ", " +
+                prefsKeyPrefix + ")");
 
         long currentCrc = getZipCrc(sourceApk);
 
@@ -113,19 +113,21 @@
             cacheLock = lockChannel.lock();
             Log.i(TAG, lockFile.getPath() + " locked");
 
-            if (!forceReload && !isModified(context, sourceApk, currentCrc)) {
+            if (!forceReload && !isModified(context, sourceApk, currentCrc, prefsKeyPrefix)) {
                 try {
-                    files = loadExistingExtractions(context, sourceApk, dexDir);
+                    files = loadExistingExtractions(context, sourceApk, dexDir, prefsKeyPrefix);
                 } catch (IOException ioe) {
                     Log.w(TAG, "Failed to reload existing extracted secondary dex files,"
                             + " falling back to fresh extraction", ioe);
                     files = performExtractions(sourceApk, dexDir);
-                    putStoredApkInfo(context, getTimeStamp(sourceApk), currentCrc, files);
+                    putStoredApkInfo(context, prefsKeyPrefix, getTimeStamp(sourceApk), currentCrc,
+                            files);
                 }
             } else {
                 Log.i(TAG, "Detected that extraction must be performed.");
                 files = performExtractions(sourceApk, dexDir);
-                putStoredApkInfo(context, getTimeStamp(sourceApk), currentCrc, files);
+                putStoredApkInfo(context, prefsKeyPrefix, getTimeStamp(sourceApk), currentCrc,
+                        files);
             }
         } finally {
             if (cacheLock != null) {
@@ -157,13 +159,14 @@
      * {@link #LOCK_FILENAME}.
      */
     private static List<ExtractedDex> loadExistingExtractions(
-            Context context, File sourceApk, File dexDir)
+            Context context, File sourceApk, File dexDir,
+            String prefsKeyPrefix)
             throws IOException {
         Log.i(TAG, "loading existing secondary dex files");
 
         final String extractedFilePrefix = sourceApk.getName() + EXTRACTED_NAME_EXT;
         SharedPreferences multiDexPreferences = getMultiDexPreferences(context);
-        int totalDexNumber = multiDexPreferences.getInt(KEY_DEX_NUMBER, 1);
+        int totalDexNumber = multiDexPreferences.getInt(prefsKeyPrefix + KEY_DEX_NUMBER, 1);
         final List<ExtractedDex> files = new ArrayList<ExtractedDex>(totalDexNumber - 1);
 
         for (int secondaryNumber = 2; secondaryNumber <= totalDexNumber; secondaryNumber++) {
@@ -171,15 +174,15 @@
             ExtractedDex extractedFile = new ExtractedDex(dexDir, fileName);
             if (extractedFile.isFile()) {
                 extractedFile.crc = getZipCrc(extractedFile);
-                long expectedCrc =
-                        multiDexPreferences.getLong(KEY_DEX_CRC + secondaryNumber, NO_VALUE);
-                long expectedModTime =
-                        multiDexPreferences.getLong(KEY_DEX_TIME + secondaryNumber, NO_VALUE);
+                long expectedCrc = multiDexPreferences.getLong(
+                        prefsKeyPrefix + KEY_DEX_CRC + secondaryNumber, NO_VALUE);
+                long expectedModTime = multiDexPreferences.getLong(
+                        prefsKeyPrefix + KEY_DEX_TIME + secondaryNumber, NO_VALUE);
                 long lastModified = extractedFile.lastModified();
                 if ((expectedModTime != lastModified)
                         || (expectedCrc != extractedFile.crc)) {
                     throw new IOException("Invalid extracted dex: " + extractedFile +
-                            ", expected modification time: "
+                            " (key \"" + prefsKeyPrefix + "\"), expected modification time: "
                             + expectedModTime + ", modification time: "
                             + lastModified + ", expected crc: "
                             + expectedCrc + ", file crc: " + extractedFile.crc);
@@ -199,10 +202,11 @@
      * Compare current archive and crc with values stored in {@link SharedPreferences}. Should be
      * called only while owning the lock on {@link #LOCK_FILENAME}.
      */
-    private static boolean isModified(Context context, File archive, long currentCrc) {
+    private static boolean isModified(Context context, File archive, long currentCrc,
+            String prefsKeyPrefix) {
         SharedPreferences prefs = getMultiDexPreferences(context);
-        return (prefs.getLong(KEY_TIME_STAMP, NO_VALUE) != getTimeStamp(archive))
-                || (prefs.getLong(KEY_CRC, NO_VALUE) != currentCrc);
+        return (prefs.getLong(prefsKeyPrefix + KEY_TIME_STAMP, NO_VALUE) != getTimeStamp(archive))
+                || (prefs.getLong(prefsKeyPrefix + KEY_CRC, NO_VALUE) != currentCrc);
     }
 
     private static long getTimeStamp(File archive) {
@@ -303,18 +307,18 @@
      * Save {@link SharedPreferences}. Should be called only while owning the lock on
      * {@link #LOCK_FILENAME}.
      */
-    private static void putStoredApkInfo(Context context, long timeStamp, long crc,
-            List<ExtractedDex> extractedDexes) {
+    private static void putStoredApkInfo(Context context, String keyPrefix, long timeStamp,
+            long crc, List<ExtractedDex> extractedDexes) {
         SharedPreferences prefs = getMultiDexPreferences(context);
         SharedPreferences.Editor edit = prefs.edit();
-        edit.putLong(KEY_TIME_STAMP, timeStamp);
-        edit.putLong(KEY_CRC, crc);
-        edit.putInt(KEY_DEX_NUMBER, extractedDexes.size() + 1);
+        edit.putLong(keyPrefix + KEY_TIME_STAMP, timeStamp);
+        edit.putLong(keyPrefix + KEY_CRC, crc);
+        edit.putInt(keyPrefix + KEY_DEX_NUMBER, extractedDexes.size() + 1);
 
         int extractedDexId = 2;
         for (ExtractedDex dex : extractedDexes) {
-            edit.putLong(KEY_DEX_CRC + extractedDexId, dex.crc);
-            edit.putLong(KEY_DEX_TIME + extractedDexId, dex.lastModified());
+            edit.putLong(keyPrefix + KEY_DEX_CRC + extractedDexId, dex.crc);
+            edit.putLong(keyPrefix + KEY_DEX_TIME + extractedDexId, dex.lastModified());
             extractedDexId++;
         }
         /* Use commit() and not apply() as advised by the doc because we need synchronous writing of