diff --git a/perlmod-macro/src/function.rs b/perlmod-macro/src/function.rs
index 4304546..e3672fe 100644
--- a/perlmod-macro/src/function.rs
+++ b/perlmod-macro/src/function.rs
@@ -116,7 +116,7 @@ pub fn handle_function(
         let pat_ty = match arg {
             syn::FnArg::Receiver(_) => bail!(arg => "cannot export self-taking methods as xsubs"),
             syn::FnArg::Typed(ref mut pt) => {
-                pt.attrs.retain(|attr| !argument_attrs.handle_attr(&attr));
+                pt.attrs.retain(|attr| !argument_attrs.handle_attr(attr));
                 argument_attrs.validate(pt.span())?;
                 &*pt
             }
@@ -328,6 +328,7 @@ struct ReturnHandling {
     wrapper_func: TokenStream,
 }
 
+#[allow(clippy::too_many_arguments)]
 fn handle_return_kind(
     attr: &FunctionAttrs,
     ret: Return,
diff --git a/perlmod-macro/src/lib.rs b/perlmod-macro/src/lib.rs
index 3fafb87..cd9661b 100644
--- a/perlmod-macro/src/lib.rs
+++ b/perlmod-macro/src/lib.rs
@@ -128,7 +128,9 @@ fn handle_error(result: Result<TokenStream, Error>) -> TokenStream {
     data
 }
 
-thread_local!(static NON_FATAL_ERRORS: RefCell<Option<TokenStream>> = RefCell::new(None));
+thread_local! {
+    static NON_FATAL_ERRORS: RefCell<Option<TokenStream>> = const { RefCell::new(None) };
+}
 
 /// The local error TLS must be freed at the end of a macro as any leftover `TokenStream` (even an
 /// empty one) will just panic between different runs as the multiple source files are handled by
diff --git a/perlmod-test/src/lib.rs b/perlmod-test/src/lib.rs
index 54e7b5a..95a030d 100644
--- a/perlmod-test/src/lib.rs
+++ b/perlmod-test/src/lib.rs
@@ -2,10 +2,12 @@
 /// been stabilized then.
 mod pkg142;
 
+/*
 #[cfg(feature = "rustmuchlater")]
 /// The following is what we ideally want to reach with future rust versions. It is technically
 /// possible on nightly with #![feature(custom_inner_attributes)]
 mod pkginline;
+*/
 
 /// A test for blessed values.
 mod bless;
diff --git a/perlmod/build.rs b/perlmod/build.rs
index 00c1064..e2d88e9 100644
--- a/perlmod/build.rs
+++ b/perlmod/build.rs
@@ -22,7 +22,7 @@ fn main() {
     Command::new("perl")
         .arg("-MDevel::PPPort")
         .arg("-e")
-        .arg(&format!(
+        .arg(format!(
             r#"Devel::PPPort::WriteFile("{ppport_h_file_string_inner}");"#
         ))
         .output()
diff --git a/perlmod/src/error.rs b/perlmod/src/error.rs
index 0a942c3..369cebc 100644
--- a/perlmod/src/error.rs
+++ b/perlmod/src/error.rs
@@ -88,7 +88,7 @@ impl fmt::Display for MagicError {
 impl std::error::Error for MagicError {}
 
 thread_local! {
-    static ERRNO: Cell<c_int> = Cell::new(0);
+    static ERRNO: Cell<c_int> = const { Cell::new(0) };
 }
 
 /// Set the perlmod-specific `errno` value. This is *not* libc's `errno`, but a separate storage
@@ -108,6 +108,11 @@ pub fn get_errno() -> c_int {
 /// This is part of the proc-macro API and is of little use to users of this crate directly.
 /// When manually implementing "xsubs" this can be used before returning as a shortcut to copying
 /// the perlmod errno value to libc.
+///
+/// # Safety
+///
+/// This is generally safe, but care should be taken as this manipulates `errno` and any C call
+/// might mess it up again.
 pub unsafe fn copy_errno_to_libc() {
     unsafe {
         libc::__errno_location().write(get_errno());
diff --git a/perlmod/src/hash.rs b/perlmod/src/hash.rs
index 64b94c5..96a56d4 100644
--- a/perlmod/src/hash.rs
+++ b/perlmod/src/hash.rs
@@ -111,7 +111,7 @@ impl Hash {
         unsafe {
             ffi::RSPL_hv_store(
                 self.hv(),
-                key.as_ptr() as *const u8 as *const libc::c_char,
+                key.as_ptr() as *const libc::c_char,
                 key.len() as i32,
                 value.into_raw(),
             );
diff --git a/perlmod/src/magic.rs b/perlmod/src/magic.rs
index fc4dfeb..47f7691 100644
--- a/perlmod/src/magic.rs
+++ b/perlmod/src/magic.rs
@@ -144,6 +144,7 @@ unsafe impl<T> Send for MagicTag<T> {}
 
 impl<T> MagicTag<T> {
     /// Create a new tag. See [`MagicSpec`] for its usage.
+    #[allow(clippy::new_without_default)]
     pub const fn new() -> Self {
         Self(ffi::MGVTBL::zero(), PhantomData)
     }
diff --git a/perlmod/src/raw_value.rs b/perlmod/src/raw_value.rs
index 81d6234..808b876 100644
--- a/perlmod/src/raw_value.rs
+++ b/perlmod/src/raw_value.rs
@@ -11,7 +11,7 @@ use crate::Value;
 pub(crate) const NAME: &str = "$__perlmod_private_RawValue";
 pub(crate) const VALUE: &str = "$__perlmod_private_raw_value";
 
-thread_local!(static SERIALIZE_RAW: RefCell<bool> = RefCell::new(false));
+thread_local!(static SERIALIZE_RAW: RefCell<bool> = const { RefCell::new(false) });
 
 pub(crate) struct RawGuard(bool);
 
diff --git a/perlmod/src/value.rs b/perlmod/src/value.rs
index d4e9176..5ac1095 100644
--- a/perlmod/src/value.rs
+++ b/perlmod/src/value.rs
@@ -225,7 +225,7 @@ impl Value {
     /// The caller must ensure that it is safe to decrease the reference count later on, or use
     /// `into_raw()` instead of letting the `Value` get dropped.
     pub unsafe fn from_raw_move(ptr: *mut SV) -> Self {
-        Self::from_scalar(unsafe { Scalar::from_raw_move(ptr as *mut SV) })
+        Self::from_scalar(unsafe { Scalar::from_raw_move(ptr) })
     }
 
     /// Create a new reference to an existing `SV` value. This will increase the value's reference
@@ -235,7 +235,7 @@ impl Value {
     ///
     /// The caller may still need to decrease the reference count for the `ptr` source value.
     pub unsafe fn from_raw_ref(ptr: *mut SV) -> Self {
-        Self::from_scalar(unsafe { Scalar::from_raw_ref(ptr as *mut SV) })
+        Self::from_scalar(unsafe { Scalar::from_raw_ref(ptr) })
     }
 
     /// Convert a [`Scalar`] to a [`Value`].