diff --git a/Android.mk b/Android.mk
index bcd6b9e..e3f60fc 100644
--- a/Android.mk
+++ b/Android.mk
@@ -29,6 +29,8 @@
 LOCAL_PACKAGE_NAME := ContactsProvider
 LOCAL_CERTIFICATE := shared
 
+LOCAL_PROGUARD_FLAG_FILES := proguard.flags
+
 include $(BUILD_PACKAGE)
 
 # Use the following include to make our test apk.
diff --git a/proguard.flags b/proguard.flags
new file mode 100644
index 0000000..957cfa3
--- /dev/null
+++ b/proguard.flags
@@ -0,0 +1,8 @@
+-keep class com.android.providers.contacts.ContactsDatabaseHelper {
+  * <init>(...);
+}
+
+# Any methods whose name is '*ForTest' are preserved.
+-keep class ** {
+  *** *ForTest(...);
+}