diff --git a/diff/diff.d.ts b/diff/diff.d.ts
index 44c7ec846..b1f947300 100644
--- a/diff/diff.d.ts
+++ b/diff/diff.d.ts
@@ -6,6 +6,7 @@
 declare namespace JsDiff {
     interface IDiffResult {
         value: string;
+        count?: number;
         added?: boolean;
         removed?: boolean;
     }