diff --git a/.github/workflows/tier1.yml b/.github/workflows/tier1.yml
index 67f408c6..be3e25f8 100644
--- a/.github/workflows/tier1.yml
+++ b/.github/workflows/tier1.yml
@@ -1,4 +1,4 @@
-on: push
+on: [push, pull_request]
 
 name: Tier 1 CI
 
diff --git a/.github/workflows/tier2.yml b/.github/workflows/tier2.yml
index c23cacca..72f5383e 100644
--- a/.github/workflows/tier2.yml
+++ b/.github/workflows/tier2.yml
@@ -1,7 +1,7 @@
 # Tier 2 platforms are expected to be compiled.
 # There are no guarantees provided for code correctness on these platforms.
 
-on: push
+on: [push, pull_request]
 
 name: Tier 2 CI
 
diff --git a/heim-derive/src/lib.rs b/heim-derive/src/lib.rs
index efbee0fd..4614aac9 100644
--- a/heim-derive/src/lib.rs
+++ b/heim-derive/src/lib.rs
@@ -24,6 +24,7 @@
     unused_results
 )]
 
+#[allow(unused_extern_crates)]
 extern crate proc_macro;
 
 use proc_macro::TokenStream;
diff --git a/heim-virt/src/sys/linux/device_tree.rs b/heim-virt/src/sys/linux/device_tree.rs
index 510cd10d..1c4a3a68 100644
--- a/heim-virt/src/sys/linux/device_tree.rs
+++ b/heim-virt/src/sys/linux/device_tree.rs
@@ -1,7 +1,14 @@
 use std::marker::Unpin;
 use std::path::Path;
 
-use heim_common::prelude::{future, Future, FutureExt, StreamExt, TryFutureExt, TryStreamExt};
+#[cfg(any(
+    target_arch = "arm",
+    target_arch = "aarch64",
+    target_arch = "powerpc",
+    target_arch = "powerpc64"
+))]
+use heim_common::prelude::TryFutureExt;
+use heim_common::prelude::{future, Future, FutureExt, StreamExt, TryStreamExt};
 use heim_runtime::fs;
 
 use crate::Virtualization;