diff --git a/surfman/src/implementation/connection.rs b/surfman/src/implementation/connection.rs
index b14b44a..d40fcfe 100644
--- a/surfman/src/implementation/connection.rs
+++ b/surfman/src/implementation/connection.rs
@@ -12,6 +12,7 @@ use super::super::surface::NativeWidget;
 #[cfg(feature = "sm-winit")]
 use winit::Window;
 
+#[deny(unconditional_recursion)]
 impl ConnectionInterface for Connection {
     type Adapter = Adapter;
     type Device = Device;
diff --git a/surfman/src/implementation/device.rs b/surfman/src/implementation/device.rs
index 29557ce..3951822 100644
--- a/surfman/src/implementation/device.rs
+++ b/surfman/src/implementation/device.rs
@@ -14,6 +14,7 @@ use super::super::surface::{NativeWidget, Surface, SurfaceTexture};
 
 use std::os::raw::c_void;
 
+#[deny(unconditional_recursion)]
 impl DeviceInterface for Device {
     type Connection = Connection;
     type Context = Context;