Android AdMob & ProGuard

On most devices, using AdMob in an obfuscated application (using ProGuard) works perfectly fine. However, on a few devices (I don't know which ones), you'll get a java.lang.NoSuchMethodError and your users will be angry. Here's the full stack trace: java.lang.RuntimeException: An error occured while executing doInBackground() at android.os.AsyncTask$3.done(AsyncTask.java:200) at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) at java.util.concurrent.FutureTask.setException(FutureTask.java:124) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) at java.util.concurrent.FutureTask.run(FutureTask.java:137) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561) at java.lang.Thread.run(Thread.java:1102) Caused by: java.lang.NoSuchMethodError: com.google.gson.Gson.a at c.a(Unknown Source) at c.doInBackground(Unknown Source) at android.os.AsyncTask$2.call(AsyncTask.java:185) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) ... 4 more When I first got this report I quickly realized it wasn't my fault, since I don't use gson. To cut to the chase, here's what I put in my procfg.txt to fix it (at least for now): -keep public class com.google.ads.** { public protected *; } -keep public class com.google.gson.** { public protected *; }