diff --git a/src/service/poc_mobile.proto b/src/service/poc_mobile.proto
index 443664a5..d1c33895 100644
--- a/src/service/poc_mobile.proto
+++ b/src/service/poc_mobile.proto
@@ -337,10 +337,14 @@ message subscriber_reward {
   uint64 discovery_location_amount = 2;
 }
 
+enum service_provider {
+  service_provider_helium_mobile = 0;
+}
+
 message service_provider_reward {
   // rewardable entity id of the service provider to which the reward will be
   // credited
-  string service_provider_id = 1;
+  service_provider service_provider_id = 1;
   /// Amount in bones rewarded
   uint64 amount = 2;
 }