diff --git a/crates/api/src/lib.rs b/crates/api/src/lib.rs
index e5196e7e1e..7ccf342ca5 100644
--- a/crates/api/src/lib.rs
+++ b/crates/api/src/lib.rs
@@ -6,8 +6,6 @@
 //! and there to implement Rust idioms. This crate also defines the actual C API
 //! itself for consumption from other languages.
 
-#![allow(improper_ctypes)]
-
 mod callable;
 mod context;
 mod externals;
diff --git a/crates/misc/py/src/lib.rs b/crates/misc/py/src/lib.rs
index 2bb164ddd2..1c7584a40c 100644
--- a/crates/misc/py/src/lib.rs
+++ b/crates/misc/py/src/lib.rs
@@ -1,5 +1,3 @@
-#![allow(improper_ctypes)]
-
 use crate::function::{wrap_into_pyfunction, Function};
 use crate::instance::Instance;
 use crate::memory::Memory;
diff --git a/crates/runtime/src/lib.rs b/crates/runtime/src/lib.rs
index 4a1f06d66c..5a48273e12 100644
--- a/crates/runtime/src/lib.rs
+++ b/crates/runtime/src/lib.rs
@@ -1,6 +1,5 @@
 //! Runtime library support for Wasmtime.
 
-#![allow(improper_ctypes)]
 #![deny(missing_docs, trivial_numeric_casts, unused_extern_crates)]
 #![warn(unused_import_braces)]
 #![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
diff --git a/crates/wasi/src/lib.rs b/crates/wasi/src/lib.rs
index c152b34132..565958f9e8 100644
--- a/crates/wasi/src/lib.rs
+++ b/crates/wasi/src/lib.rs
@@ -1,5 +1,3 @@
-#![allow(improper_ctypes)]
-
 mod instantiate;
 pub mod old;
 
diff --git a/crates/wasi/src/old/snapshot_0/mod.rs b/crates/wasi/src/old/snapshot_0/mod.rs
index ef699ce0b6..b4ffd25440 100644
--- a/crates/wasi/src/old/snapshot_0/mod.rs
+++ b/crates/wasi/src/old/snapshot_0/mod.rs
@@ -1,5 +1,3 @@
-#![allow(improper_ctypes)]
-
 extern crate alloc;
 
 mod instantiate;
diff --git a/crates/wast/src/spectest.rs b/crates/wast/src/spectest.rs
index fb2cb96de6..c180a7689c 100644
--- a/crates/wast/src/spectest.rs
+++ b/crates/wast/src/spectest.rs
@@ -1,5 +1,3 @@
-#![allow(improper_ctypes)]
-
 use anyhow::Result;
 use std::collections::HashMap;
 use std::rc::Rc;