diff --git a/protos/SignalService.proto b/protos/SignalService.proto
index 92a62d6be2..6279e666c9 100644
--- a/protos/SignalService.proto
+++ b/protos/SignalService.proto
@@ -279,6 +279,7 @@ message ReceiptMessage {
   enum Type {
     DELIVERY = 0;
     READ     = 1;
+    VIEWED   = 2;
   }
 
   optional Type   type      = 1;
diff --git a/ts/textsecure.d.ts b/ts/textsecure.d.ts
index 9ab358aed5..ca88d2efdf 100644
--- a/ts/textsecure.d.ts
+++ b/ts/textsecure.d.ts
@@ -893,6 +893,7 @@ export declare namespace ReceiptMessageClass {
   class Type {
     static DELIVERY: number;
     static READ: number;
+    static VIEWED: number;
   }
 }