diff --git a/knockout.mapping/knockout.mapping-2.0.d.ts b/knockout.mapping/knockout.mapping-2.0.d.ts
index e8c5b519df..6f22678268 100644
--- a/knockout.mapping/knockout.mapping-2.0.d.ts
+++ b/knockout.mapping/knockout.mapping-2.0.d.ts
@@ -5,11 +5,11 @@
 
 
 interface KnockoutMappingOptions {
-    ignore;
-    include;
-    copy;
-    mappedProperties;
-    deferEvaluation;
+    ignore? : string[];
+    include? : string[];
+    copy? : string[];
+    mappedProperties? : string[];
+    deferEvaluation? :  bool;
 }
 
 interface KnockoutMapping {
@@ -28,4 +28,4 @@ interface KnockoutMapping {
 
 interface KnockoutStatic {
     mapping: KnockoutMapping;
-}
\ No newline at end of file
+}