diff --git a/src/stdlib/WebSharper.Main.Proxies/ResultModule.fs b/src/stdlib/WebSharper.Main.Proxies/ResultModule.fs
index 26b0a0cf..a0849815 100644
--- a/src/stdlib/WebSharper.Main.Proxies/ResultModule.fs
+++ b/src/stdlib/WebSharper.Main.Proxies/ResultModule.fs
@@ -24,18 +24,23 @@
      FSharp.Core, Culture=neutral, \
      PublicKeyToken=b03f5f7f11d50a3a">]
 module private WebSharper.ResultModuleProxy
-    
+
 let Bind f r =
     match r with
     | Ok x -> f x
     | Error e -> Error e
-        
+
 let Map f r =
     match r with
     | Ok x -> Ok (f x)
     | Error e -> Error e
-        
+
 let MapError f r =
     match r with
     | Ok x -> Ok x
-    | Error e -> Error (f e)    
+    | Error e -> Error (f e)
+
+let isOk r =
+    match r with
+    | Ok _ -> true
+    | _ -> false
\ No newline at end of file
diff --git a/tests/WebSharper.Tests/Result.fs b/tests/WebSharper.Tests/Result.fs
index c4b1a1f3..e3eb7f36 100644
--- a/tests/WebSharper.Tests/Result.fs
+++ b/tests/WebSharper.Tests/Result.fs
@@ -57,4 +57,11 @@ let Tests =
             equal (r2 |> Result.bind (fun x -> Ok())) (Error "e")
         }
 
+        Test "isOk" {
+            let r = Ok 3
+            let r2 = Error "e"
+            equal (r |> Result.isOk) true
+            equal (r2 |> Result.isOk) false
+        }
+
     }