diff --git a/app/src/main/java/info/nightscout/androidaps/plugins/NSClientInternal/services/NSClientService.java b/app/src/main/java/info/nightscout/androidaps/plugins/NSClientInternal/services/NSClientService.java
index 3fd608475f..74f0577bb5 100644
--- a/app/src/main/java/info/nightscout/androidaps/plugins/NSClientInternal/services/NSClientService.java
+++ b/app/src/main/java/info/nightscout/androidaps/plugins/NSClientInternal/services/NSClientService.java
@@ -9,6 +9,7 @@ import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.PowerManager;
 
+import com.crashlytics.android.Crashlytics;
 import com.google.common.base.Charsets;
 import com.google.common.hash.Hashing;
 import com.j256.ormlite.dao.CloseableIterator;
@@ -352,7 +353,13 @@ public class NSClientService extends Service {
         public void call(final Object... args) {
             if (Config.detailedLog)
                 MainApp.bus().post(new EventNSClientNewLog("ALARM", "received"));
-            JSONObject data = (JSONObject) args[0];
+            JSONObject data;
+            try {
+                data = (JSONObject) args[0];
+            } catch (ClassCastException e) {
+                Crashlytics.log("Wrong alarm from NS: " + args[0]);
+                return;
+            }
             BroadcastAlarm.handleAlarm(data, getApplicationContext());
             log.debug(data.toString());
         }