diff --git a/react/react-addons-global.d.ts b/react/react-addons-global.d.ts
index 891e0d1017..bccd3f4275 100644
--- a/react/react-addons-global.d.ts
+++ b/react/react-addons-global.d.ts
@@ -77,9 +77,9 @@ declare module React {
     // ----------------------------------------------------------------------
 
     interface UpdateSpec {
-        $set: any;
-        $merge: {};
-        $apply(value: any): any;
+        $set?: any;
+        $merge?: {};
+        $apply?(value: any): any;
         // [key: string]: UpdateSpec;
     }
 
diff --git a/react/react-addons.d.ts b/react/react-addons.d.ts
index caf0fa8e0a..c4e768f27b 100644
--- a/react/react-addons.d.ts
+++ b/react/react-addons.d.ts
@@ -812,9 +812,9 @@ declare module "react/addons" {
     // ----------------------------------------------------------------------
 
     interface UpdateSpec {
-        $set: any;
-        $merge: {};
-        $apply(value: any): any;
+        $set?: any;
+        $merge?: {};
+        $apply?(value: any): any;
         // [key: string]: UpdateSpec;
     }