diff --git a/types/knockout/index.d.ts b/types/knockout/index.d.ts
index eadd28d875..d96d22a9a2 100644
--- a/types/knockout/index.d.ts
+++ b/types/knockout/index.d.ts
@@ -10,7 +10,6 @@
 //                 Retsam <https://github.com/Retsam>
 //                 Rey Pena <https://github.com/ReyPena>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-// TypeScript Version: 2.3
 
 interface KnockoutSubscribableFunctions<T> {
     /**
@@ -286,6 +285,7 @@ interface KnockoutObservableStatic {
     fn: KnockoutObservableFunctions<any>;
 
     <T>(value: T): KnockoutObservable<T>;
+    <T>(value: any): KnockoutObservable<T>;
     <T = any>(value: null): KnockoutObservable<T | null>
     <T = any>(): KnockoutObservable<T | undefined>
 }
diff --git a/types/knockout/package.json b/types/knockout/package.json
index d17715e91f..86892b38c9 100644
--- a/types/knockout/package.json
+++ b/types/knockout/package.json
@@ -2,9 +2,9 @@
     "private": true,
     "types": "index",
     "typesVersions": {
-        ">=4.0.0-0": {
+        "<=3.9": {
             "*": [
-                "ts4.0/*"
+                "ts3.9/*"
             ]
         }
     }
diff --git a/types/knockout/ts4.0/index.d.ts b/types/knockout/ts3.9/index.d.ts
similarity index 98%
rename from types/knockout/ts4.0/index.d.ts
rename to types/knockout/ts3.9/index.d.ts
index d96d22a9a2..e1100d7c04 100644
--- a/types/knockout/ts4.0/index.d.ts
+++ b/types/knockout/ts3.9/index.d.ts
@@ -1,16 +1,3 @@
-// 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>,
-//                 Mathias Lorenzen <https://github.com/ffMathy>,
-//                 Leonardo Lombardi <https://github.com/ltlombardi>
-//                 Retsam <https://github.com/Retsam>
-//                 Rey Pena <https://github.com/ReyPena>
-// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-
 interface KnockoutSubscribableFunctions<T> {
     /**
      * Notify subscribers of knockout "change" event. This doesn't actually change the observable value.
@@ -285,7 +272,6 @@ interface KnockoutObservableStatic {
     fn: KnockoutObservableFunctions<any>;
 
     <T>(value: T): KnockoutObservable<T>;
-    <T>(value: any): KnockoutObservable<T>;
     <T = any>(value: null): KnockoutObservable<T | null>
     <T = any>(): KnockoutObservable<T | undefined>
 }
diff --git a/types/knockout/ts4.0/test/index.ts b/types/knockout/ts3.9/test/index.ts
similarity index 100%
rename from types/knockout/ts4.0/test/index.ts
rename to types/knockout/ts3.9/test/index.ts
diff --git a/types/knockout/ts4.0/test/readonly.ts b/types/knockout/ts3.9/test/readonly.ts
similarity index 100%
rename from types/knockout/ts4.0/test/readonly.ts
rename to types/knockout/ts3.9/test/readonly.ts
diff --git a/types/knockout/ts4.0/test/templatingBehaviors.ts b/types/knockout/ts3.9/test/templatingBehaviors.ts
similarity index 100%
rename from types/knockout/ts4.0/test/templatingBehaviors.ts
rename to types/knockout/ts3.9/test/templatingBehaviors.ts
diff --git a/types/knockout/ts4.0/tsconfig.json b/types/knockout/ts3.9/tsconfig.json
similarity index 100%
rename from types/knockout/ts4.0/tsconfig.json
rename to types/knockout/ts3.9/tsconfig.json
diff --git a/types/knockout/ts4.0/tslint.json b/types/knockout/ts3.9/tslint.json
similarity index 100%
rename from types/knockout/ts4.0/tslint.json
rename to types/knockout/ts3.9/tslint.json