diff --git a/packages/firestore/src/platform/browser/webchannel_connection.ts b/packages/firestore/src/platform/browser/webchannel_connection.ts
index 38d78996b6e..52d6aa712cd 100644
--- a/packages/firestore/src/platform/browser/webchannel_connection.ts
+++ b/packages/firestore/src/platform/browser/webchannel_connection.ts
@@ -396,7 +396,9 @@ export class WebChannelConnection extends RestConnection {
     );
 
     unguardedEventListen<StatEvent>(requestStats, Event.STAT_EVENT, event => {
-      if (event.stat === Stat.PROXY) {
+      if (event.stat === 0) {
+        return;
+      } else if (event.stat === Stat.PROXY) {
         logDebug(
           LOG_TAG,
           `RPC '${rpcName}' stream ${streamId} detected buffering proxy`
@@ -406,6 +408,11 @@ export class WebChannelConnection extends RestConnection {
           LOG_TAG,
           `RPC '${rpcName}' stream ${streamId} detected no buffering proxy`
         );
+      } else {
+        logWarn(
+          LOG_TAG,
+          `STAT_EVENT: RPC '${rpcName}' stream ${streamId} event ${event.stat}`
+        );
       }
     });
 
diff --git a/packages/webchannel-wrapper/src/index.d.ts b/packages/webchannel-wrapper/src/index.d.ts
index 776bb8e8634..e8bc57cbd6a 100644
--- a/packages/webchannel-wrapper/src/index.d.ts
+++ b/packages/webchannel-wrapper/src/index.d.ts
@@ -38,8 +38,28 @@ export var Event: {
 export var Stat: {
   PROXY: number;
   NOPROXY: number;
+  BACKCHANNEL_DEAD: number;
+  BACKCHANNEL_MISSING: number;
+  BROWSER_OFFLINE: number;
+  CONNECT_ATTEMPT: number;
+  ERROR_NETWORK: number;
+  ERROR_OTHER: number;
+  REQUEST_BAD_DATA: number;
+  REQUEST_BAD_STATUS: number;
+  REQUEST_INCOMPLETE_DATA: number;
+  REQUEST_NO_DATA: number;
+  REQUEST_TIMEOUT: number;
+  REQUEST_UNKNOWN_SESSION_ID: number;
+  TEST_STAGE_ONE_FAILED: number;
+  TEST_STAGE_ONE_START: number;
+  TEST_STAGE_TWO_DATA_BOTH: number;
+  TEST_STAGE_TWO_DATA_ONE: number;
+  TEST_STAGE_TWO_DATA_TWO: number;
+  TEST_STAGE_TWO_FAILED: number;
+  TEST_STAGE_TWO_START: number;
 };
 
+
 export var ErrorCode: {
   NO_ERROR: number;
   HTTP_ERROR: number;