diff --git a/proguard.flags b/proguard.flags
index 979e6bc..cae5d2c 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -1,3 +1,25 @@
 -keep class * extends java.util.ListResourceBundle {
     protected Object[][] getContents();
-}
\ No newline at end of file
+}
+
+# Keep SafeParcelable value, needed for reflection. This is required to support backwards
+# compatibility of some classes.
+-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
+    public static final *** NULL;
+}
+
+# Keep the names of classes/members we need for client functionality.
+-keepnames @com.google.android.gms.common.annotation.KeepName class *
+-keepclassmembernames class * {
+    @com.google.android.gms.common.annotation.KeepName *;
+}
+
+# Needed for Parcelable/SafeParcelable Creators to not get stripped
+-keepnames class * implements android.os.Parcelable {
+    public static final ** CREATOR;
+}
+
+# Needed when building against the Marshmallow SDK
+-dontwarn org.apache.http.**
+-dontwarn android.support.**
+-dontwarn com.google.android.gms.**
\ No newline at end of file
diff --git a/res/values/version.xml b/res/values/version.xml
deleted file mode 100644
index 1e7fd4e..0000000
--- a/res/values/version.xml
+++ /dev/null
@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-    <integer name="google_play_services_version">4323000</integer>
-</resources>