Function overloading between modules

[JN via Digitalmars-d-learn]

Is this expected behaviour?

bar.d
---
void foo(string s)
{
}

app.d
---

import std.stdio;
import bar;

void foo(int x)
{
}

void main()
{
  foo("hi");
};


===
Error: function app.foo (int x) is not callable using argument 
types (string)