diff --git a/crates/api/src/lib.rs b/crates/api/src/lib.rs
index 065b8c7bae09..54039179b643 100644
--- a/crates/api/src/lib.rs
+++ b/crates/api/src/lib.rs
@@ -1,5 +1,6 @@
 //! Wasmtime embed API. Based on wasm-c-api.
 
+#![allow(improper_ctypes)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
 mod callable;
diff --git a/crates/misc/py/src/lib.rs b/crates/misc/py/src/lib.rs
index a9bfbbfd13d5..a3bc0be36fb3 100644
--- a/crates/misc/py/src/lib.rs
+++ b/crates/misc/py/src/lib.rs
@@ -1,3 +1,5 @@
+#![allow(improper_ctypes)]
+
 use crate::import::into_instance_from_obj;
 use crate::instance::Instance;
 use crate::memory::Memory;
diff --git a/crates/runtime/src/lib.rs b/crates/runtime/src/lib.rs
index c7b597b438a8..12e79a7153b7 100644
--- a/crates/runtime/src/lib.rs
+++ b/crates/runtime/src/lib.rs
@@ -1,5 +1,6 @@
 //! Runtime library support for Wasmtime.
 
+#![allow(improper_ctypes)]
 #![deny(missing_docs, trivial_numeric_casts, unused_extern_crates)]
 #![warn(unused_import_braces)]
 #![cfg_attr(feature = "std", deny(unstable_features))]
diff --git a/crates/wasi/src/lib.rs b/crates/wasi/src/lib.rs
index 8a2d14162510..7ef37df6b7d0 100644
--- a/crates/wasi/src/lib.rs
+++ b/crates/wasi/src/lib.rs
@@ -1,3 +1,5 @@
+#![allow(improper_ctypes)]
+
 extern crate alloc;
 
 mod instantiate;
diff --git a/crates/wast/src/spectest.rs b/crates/wast/src/spectest.rs
index 63c4f38878ca..e1e3d9a1bd70 100644
--- a/crates/wast/src/spectest.rs
+++ b/crates/wast/src/spectest.rs
@@ -1,3 +1,5 @@
+#![allow(improper_ctypes)]
+
 use alloc::rc::Rc;
 use core::cell::RefCell;
 use cranelift_codegen::ir::types;