diff --git a/Cargo.lock b/Cargo.lock
index 57cb945169..86e8e96a26 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -624,6 +624,7 @@ name = "wgpu-native"
 version = "0.4.0"
 dependencies = [
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "raw-window-handle 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "wgpu-core 0.1.0",
diff --git a/wgpu-native/Cargo.toml b/wgpu-native/Cargo.toml
index dc66ec014a..d1f6e01294 100644
--- a/wgpu-native/Cargo.toml
+++ b/wgpu-native/Cargo.toml
@@ -29,3 +29,5 @@ version = "0.1"
 lazy_static = "1.1"
 parking_lot = "0.9"
 raw-window-handle = "0.3"
+libc = {version="0.2", features=[]}
+
diff --git a/wgpu-native/src/device.rs b/wgpu-native/src/device.rs
index 7180d3ada1..32553b1fb3 100644
--- a/wgpu-native/src/device.rs
+++ b/wgpu-native/src/device.rs
@@ -8,6 +8,8 @@ use core::{gfx_select, hub::Token, id};
 
 use std::{marker::PhantomData, slice};
 
+use libc::{c_ulong};
+
 pub type RequestAdapterCallback =
     unsafe extern "C" fn(id: id::AdapterId, userdata: *mut std::ffi::c_void);
 pub type BufferMapReadCallback =
@@ -78,7 +80,7 @@ pub fn wgpu_create_surface(raw_handle: raw_window_handle::RawWindowHandle) -> id
 #[no_mangle]
 pub extern "C" fn wgpu_create_surface_from_xlib(
     display: *mut *const std::ffi::c_void,
-    window: u64,
+    window: c_ulong,
 ) -> id::SurfaceId {
     use raw_window_handle::unix::XlibHandle;
     wgpu_create_surface(raw_window_handle::RawWindowHandle::Xlib(XlibHandle {