How to use static extension methods with statically resolved type parameters?

I'd like to use statically resolved type parameters with some extension methods I added to built-in types, like float32 and int32, so I tried the following:

module Foo =
    type System.Single with
        static member Bar x = x + 1.0f

    let inline bar (x : ^a) =
        (^a : (static member Bar : ^a -> ^a) x)

open Foo
[<EntryPoint>]
let main argv =
    System.Console.WriteLine (bar 1.0f) (* Compilation fails here *)
    0

The compiler complains that The type 'float32' doesn't support the operator 'Bar'. What am I doing wrong?