diff --git a/types/knockout-amd-helpers/index.d.ts b/types/knockout-amd-helpers/index.d.ts
index d12c8d9a8f..6f3a5493e1 100644
--- a/types/knockout-amd-helpers/index.d.ts
+++ b/types/knockout-amd-helpers/index.d.ts
@@ -2,10 +2,10 @@
 // Project: https://github.com/rniemeyer/knockout-amd-helpers
 // Definitions by: David Sichau <https://github.com/DavidSichau>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
-
 interface KnockoutAMDModule {
     baseDir: string;
     initializer: string;
diff --git a/types/knockout-secure-binding/index.d.ts b/types/knockout-secure-binding/index.d.ts
index 84a432738b..f7c7500cff 100644
--- a/types/knockout-secure-binding/index.d.ts
+++ b/types/knockout-secure-binding/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/brianmhunt/knockout-secure-binding
 // Definitions by: Pine Mizune <https://github.com/pine613>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
@@ -28,4 +29,4 @@ declare module "knockout-secure-binding" {
     };
 
     export = klass;
-}
\ No newline at end of file
+}
diff --git a/types/knockout-transformations/index.d.ts b/types/knockout-transformations/index.d.ts
index 958eb99fb6..5fab318c1b 100644
--- a/types/knockout-transformations/index.d.ts
+++ b/types/knockout-transformations/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/One-com/knockout-transformations
 // Definitions by: John Reilly <https://github.com/johnnyreilly>, Wim Looman <https://github.com/Nemo157>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.deferred.updates/index.d.ts b/types/knockout.deferred.updates/index.d.ts
index 89fb752089..c02f371277 100644
--- a/types/knockout.deferred.updates/index.d.ts
+++ b/types/knockout.deferred.updates/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/mbest/knockout-deferred-updates
 // Definitions by: Sebastián Galiano <https://github.com/sgaliano>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
@@ -42,4 +43,4 @@ interface KnockoutUtils {
 // Deferred extender
 interface KnockoutExtenders {
     deferred(target: any, value: boolean): any;
-}
\ No newline at end of file
+}
diff --git a/types/knockout.editables/index.d.ts b/types/knockout.editables/index.d.ts
index 4a4ed59d3b..5167287e7e 100644
--- a/types/knockout.editables/index.d.ts
+++ b/types/knockout.editables/index.d.ts
@@ -2,6 +2,7 @@
 // Project: http://romanych.github.com/ko.editables/
 // Definitions by: Boris Yankov <https://github.com/borisyankov>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.es5/index.d.ts b/types/knockout.es5/index.d.ts
index ce41db0d73..0ae2526c25 100644
--- a/types/knockout.es5/index.d.ts
+++ b/types/knockout.es5/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/SteveSanderson/knockout-es5
 // Definitions by: Sebastián Galiano <https://github.com/sgaliano>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.mapper/index.d.ts b/types/knockout.mapper/index.d.ts
index 747a3d1f4a..d77f3e8f22 100644
--- a/types/knockout.mapper/index.d.ts
+++ b/types/knockout.mapper/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/LucasLorentz/knockout.mapper
 // Definitions by: Brandon Meyer <https://github.com/BMeyerKC>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.mapping/index.d.ts b/types/knockout.mapping/index.d.ts
index 23f7aae8b5..e6d5fe2f6c 100644
--- a/types/knockout.mapping/index.d.ts
+++ b/types/knockout.mapping/index.d.ts
@@ -1,7 +1,9 @@
 // Type definitions for Knockout.Mapping 2.0
 // Project: https://github.com/SteveSanderson/knockout.mapping
-// Definitions by: Boris Yankov <https://github.com/borisyankov>
+// Definitions by: Boris Yankov <https://github.com/borisyankov>, 
+//                 Mathias Lorenzen <https://github.com/ffMathy>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
@@ -33,17 +35,25 @@ declare global {
         update?: (options: KnockoutMappingUpdateOptions) => void;
         key?: (data: any) => any;
     }
+    
+    type KnockoutObservableType<T> = {
+        [P in keyof T]: KnockoutObservable<T[P]>;
+    };
 
     interface KnockoutMapping {
         isMapped(viewModel: any): boolean;
-        fromJS(jsObject: any): any;
-        fromJS(jsObject: any, targetOrOptions: any): any;
-        fromJS(jsObject: any, inputOptions: any, target: any): any;
+        fromJS<T>(jsObject: T[]): KnockoutObservableType<T>[];
+        fromJS<T>(jsObject: T[], targetOrOptions: any): KnockoutObservableType<T>[];
+        fromJS<T>(jsObject: T[], inputOptions: any, target: any): KnockoutObservableType<T>[];
+        fromJS<T>(jsObject: T): KnockoutObservableType<T>;
+        fromJS<T>(jsObject: T, targetOrOptions: any): KnockoutObservableType<T>;
+        fromJS<T>(jsObject: T, inputOptions: any, target: any): KnockoutObservableType<T>;
         fromJSON(jsonString: string): any;
         fromJSON(jsonString: string, targetOrOptions: any): any;
         fromJSON(jsonString: string, inputOptions: any, target: any): any;
-        toJS(rootObject: any, options?: KnockoutMappingOptions): any;
-        toJSON(rootObject: any, options?: KnockoutMappingOptions): any;
+        toJS<T>(rootObject: KnockoutObservableArray<T>|T, options?: KnockoutMappingOptions): T[];
+        toJS<T>(rootObject: KnockoutObservableType<T>|T, options?: KnockoutMappingOptions): T;
+        toJSON(rootObject: any, options?: KnockoutMappingOptions): string;
         defaultOptions(): KnockoutMappingOptions;
         resetDefaultOptions(): void;
         getType(x: any): any;
diff --git a/types/knockout.postbox/index.d.ts b/types/knockout.postbox/index.d.ts
index 56afa3a2b6..d7e967bcb9 100644
--- a/types/knockout.postbox/index.d.ts
+++ b/types/knockout.postbox/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/rniemeyer/knockout-postbox
 // Definitions by: Judah Gabriel Himango <https://debuggerdotbreak.wordpress.com>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.projections/index.d.ts b/types/knockout.projections/index.d.ts
index aae8b55f57..bed2ac82ca 100644
--- a/types/knockout.projections/index.d.ts
+++ b/types/knockout.projections/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/stevesanderson/knockout-projections
 // Definitions by: John Reilly <https://github.com/johnnyreilly>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.punches/index.d.ts b/types/knockout.punches/index.d.ts
index aec2860bd9..c378d68c37 100644
--- a/types/knockout.punches/index.d.ts
+++ b/types/knockout.punches/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/mbest/knockout.punches
 // Definitions by: Stephen Lautier <https://github.com/johnnyreilly>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.rx/index.d.ts b/types/knockout.rx/index.d.ts
index 82a5473f1c..fea2c5175b 100644
--- a/types/knockout.rx/index.d.ts
+++ b/types/knockout.rx/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/Igorbek/knockout.rx
 // Definitions by: Igor Oleinikov <https://github.com/Igorbek>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout"/>
 /// <reference types="rx"/>
diff --git a/types/knockout.validation/index.d.ts b/types/knockout.validation/index.d.ts
index 8b0300bd7f..e302ee6279 100644
--- a/types/knockout.validation/index.d.ts
+++ b/types/knockout.validation/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/ericmbarnard/Knockout-Validation
 // Definitions by: Dan Ludwig <https://github.com/danludwig>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout.viewmodel/index.d.ts b/types/knockout.viewmodel/index.d.ts
index 5e57afb449..2ea6815531 100644
--- a/types/knockout.viewmodel/index.d.ts
+++ b/types/knockout.viewmodel/index.d.ts
@@ -2,6 +2,7 @@
 // Project: http://coderenaissance.github.com/knockout.viewmodel/
 // Definitions by: Oisin Grehan <https://github.com/oising>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/knockout/index.d.ts b/types/knockout/index.d.ts
index 4ef3bc8739..8d035ed8d2 100644
--- a/types/knockout/index.d.ts
+++ b/types/knockout/index.d.ts
@@ -1,12 +1,13 @@
 // Type definitions for Knockout v3.4.0
 // Project: http://knockoutjs.com
-// Definitions by: Boris Yankov <https://github.com/borisyankov/>
-//                 Igor Oleinikov <https://github.com/Igorbek/>
-//                 Clément Bourgeois <https://github.com/moonpyk/>
-//                 Matt Brooks <https://github.com/EnableSoftware>
-//                 Benjamin Eckardt <https://github.com/BenjaminEckardt>
+// Definitions by: Boris Yankov <https://github.com/borisyankov>, 
+//                 Igor Oleinikov <https://github.com/Igorbek>, 
+//                 Clément Bourgeois <https://github.com/moonpyk>, 
+//                 Matt Brooks <https://github.com/EnableSoftware>, 
+//                 Benjamin Eckardt <https://github.com/BenjaminEckardt>, 
+//                 Mathias Lorenzen <https://github.com/ffMathy>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-
+// TypeScript Version: 2.3
 
 interface KnockoutExtensionFunctions {
     [key: string]: any;
diff --git a/types/knockout/test/index.ts b/types/knockout/test/index.ts
index e3f7820f94..9913b64fa8 100644
--- a/types/knockout/test/index.ts
+++ b/types/knockout/test/index.ts
@@ -484,8 +484,8 @@ function test_mappingplugin() {
     ko.mapping.fromJS(data, {}, this);
 
     var alice, aliceMappingOptions, bob, bobMappingOptions;
-    var viewModel = ko.mapping.fromJS(alice, aliceMappingOptions);
-    ko.mapping.fromJS(bob, bobMappingOptions, viewModel);
+    var aliceViewModel = ko.mapping.fromJS(alice, aliceMappingOptions);
+    ko.mapping.fromJS(bob, bobMappingOptions, aliceViewModel);
 
     var obj;
     var result = ko.mapping.fromJS(obj, {
diff --git a/types/kolite/knockout.activity.d.ts b/types/kolite/knockout.activity.d.ts
index 8a1f1a0fac..8022e18cff 100644
--- a/types/kolite/knockout.activity.d.ts
+++ b/types/kolite/knockout.activity.d.ts
@@ -2,7 +2,7 @@
 // Project: https://github.com/CodeSeven/kolite
 // Definitions by: Boris Yankov <https://github.com/borisyankov>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-
+// TypeScript Version: 2.3
 
 /// <reference types="jquery" />
 /// <reference types="knockout" />
diff --git a/types/kolite/knockout.command.d.ts b/types/kolite/knockout.command.d.ts
index ff509dbd16..786bbcfaae 100644
--- a/types/kolite/knockout.command.d.ts
+++ b/types/kolite/knockout.command.d.ts
@@ -2,7 +2,7 @@
 // Project: https://github.com/CodeSeven/kolite
 // Definitions by: Boris Yankov <https://github.com/borisyankov>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-
+// TypeScript Version: 2.3
 
 /// <reference types="jquery" />
 /// <reference types="knockout" />
diff --git a/types/kolite/knockout.dirtyFlag.d.ts b/types/kolite/knockout.dirtyFlag.d.ts
index 1c63ce8b7d..2f63a110e0 100644
--- a/types/kolite/knockout.dirtyFlag.d.ts
+++ b/types/kolite/knockout.dirtyFlag.d.ts
@@ -2,7 +2,7 @@
 // Project: https://github.com/CodeSeven/kolite
 // Definitions by: Boris Yankov <https://github.com/borisyankov>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-
+// TypeScript Version: 2.3
 
 /// <reference types="jquery" />
 /// <reference types="knockout" />
diff --git a/types/underscore-ko/index.d.ts b/types/underscore-ko/index.d.ts
index 8b04a28f39..25413677ef 100644
--- a/types/underscore-ko/index.d.ts
+++ b/types/underscore-ko/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/kamranayub/UnderscoreKO
 // Definitions by: Maurits Elbers <https://github.com/MagicMau>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />
 
diff --git a/types/valerie/index.d.ts b/types/valerie/index.d.ts
index cab8ee7467..733014b37e 100644
--- a/types/valerie/index.d.ts
+++ b/types/valerie/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/davewatts/valerie
 // Definitions by: Howard Richards <https://github.com/conficient>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="knockout" />