diff --git a/constants.h b/constants.h
index 5b0ba8c..b221331 100644
--- a/constants.h
+++ b/constants.h
@@ -78,6 +78,7 @@
 typedef enum {
   kDownloadSourceHttpsServer, // UMA Binary representation: 0001
   kDownloadSourceHttpServer,  // UMA Binary representation: 0010
+  kDownloadSourceHttpPeer,    // UMA Binary representation: 0100
 
   // Note: Add new sources only above this line.
   kNumDownloadSources