diff --git a/react/react-addons-global.d.ts b/react/react-addons-global.d.ts
index 3e028f5f0..bccd3f427 100644
--- a/react/react-addons-global.d.ts
+++ b/react/react-addons-global.d.ts
@@ -79,7 +79,7 @@ declare module React {
     interface UpdateSpec {
         $set?: any;
         $merge?: {};
-        $apply(value: any)?: any;
+        $apply?(value: any): any;
         // [key: string]: UpdateSpec;
     }
 
diff --git a/react/react-addons.d.ts b/react/react-addons.d.ts
index d61bf4221..c4e768f27 100644
--- a/react/react-addons.d.ts
+++ b/react/react-addons.d.ts
@@ -814,7 +814,7 @@ declare module "react/addons" {
     interface UpdateSpec {
         $set?: any;
         $merge?: {};
-        $apply(value: any)?: any;
+        $apply?(value: any): any;
         // [key: string]: UpdateSpec;
     }