diff --git a/dlls/jscript/number.c b/dlls/jscript/number.c
index 598de42093e..d909cdb851a 100644
--- a/dlls/jscript/number.c
+++ b/dlls/jscript/number.c
@@ -105,8 +105,18 @@ static HRESULT Number_toPrecision(DispatchEx *dispex, LCID lcid, WORD flags, DIS
 static HRESULT Number_valueOf(DispatchEx *dispex, LCID lcid, WORD flags, DISPPARAMS *dp,
         VARIANT *retv, jsexcept_t *ei, IServiceProvider *sp)
 {
-    FIXME("\n");
-    return E_NOTIMPL;
+    TRACE("\n");
+
+    if(!is_class(dispex, JSCLASS_NUMBER)) {
+        FIXME("throw TypeError\n");
+        return E_FAIL;
+    }
+
+    if(retv) {
+        NumberInstance *number = (NumberInstance*)dispex;
+        *retv = number->num;
+    }
+    return S_OK;
 }
 
 static HRESULT Number_hasOwnProperty(DispatchEx *dispex, LCID lcid, WORD flags, DISPPARAMS *dp,
@@ -198,19 +208,13 @@ static HRESULT NumberConstr_value(DispatchEx *dispex, LCID lcid, WORD flags, DIS
     case DISPATCH_CONSTRUCT: {
         DispatchEx *obj;
 
-        switch(arg_cnt(dp)) {
-        case 0:
-            V_VT(&num) = VT_I4;
-            V_I4(&num) = 0;
-            break;
-        case 1:
+        if(arg_cnt(dp)) {
             hres = to_number(dispex->ctx, get_arg(dp, 0), ei, &num);
             if(FAILED(hres))
                 return hres;
-            break;
-        default:
-            FIXME("unimplemented args\n");
-            return E_NOTIMPL;
+        }else {
+            V_VT(&num) = VT_I4;
+            V_I4(&num) = 0;
         }
 
         hres = create_number(dispex->ctx, &num, &obj);
@@ -258,6 +262,7 @@ HRESULT create_number_constr(script_ctx_t *ctx, DispatchEx **ret)
     if(FAILED(hres))
         return hres;
 
+    V_VT(&number->num) = VT_I4;
     hres = create_builtin_function(ctx, NumberConstr_value, PROPF_CONSTR, &number->dispex, ret);
 
     jsdisp_release(&number->dispex);
diff --git a/dlls/jscript/tests/api.js b/dlls/jscript/tests/api.js
index 3bb3ddf5410..602b7dfd6a7 100644
--- a/dlls/jscript/tests/api.js
+++ b/dlls/jscript/tests/api.js
@@ -362,6 +362,15 @@ ok(Number() === 0, "Number() = " + Number());
 ok(Number(false) === 0, "Number(false) = " + Number(false));
 ok(Number("43") === 43, "Number('43') = " + Number("43"));
 
+tmp = (new Number(1)).valueOf();
+ok(tmp === 1, "(new Number(1)).valueOf = " + tmp);
+tmp = (new Number(1,2)).valueOf();
+ok(tmp === 1, "(new Number(1,2)).valueOf = " + tmp);
+tmp = (new Number()).valueOf();
+ok(tmp === 0, "(new Number()).valueOf = " + tmp);
+tmp = Number.prototype.valueOf();
+ok(tmp === 0, "Number.prototype.valueOf = " + tmp);
+
 tmp = Math.min(1);
 ok(tmp === 1, "Math.min(1) = " + tmp);