diff --git a/knockout/tests/knockout-tests.ts b/knockout/tests/knockout-tests.ts
index 82b5aa25c..2b9253d5c 100644
--- a/knockout/tests/knockout-tests.ts
+++ b/knockout/tests/knockout-tests.ts
@@ -72,7 +72,7 @@ function test_computed() {
         this.acceptedNumericValue = ko.observable(123);
         this.lastInputWasValid = ko.observable(true);
 
-        this.attemptedValue = ko.computed({
+        this.attemptedValue = ko.computed<number>({
             read: this.acceptedNumericValue,
             write: function (value) {
                 if (isNaN(value))
@@ -284,7 +284,7 @@ function test_more() {
     };
 
     ko.extenders.numeric = function (target, precision) {
-        var result = ko.computed({
+        var result = ko.computed<any>({
             read: target,
             write: function (newValue) {
                 var current = target(),