diff --git a/derive/src/util.rs b/derive/src/util.rs
index a0d848b69..fff2a403b 100644
--- a/derive/src/util.rs
+++ b/derive/src/util.rs
@@ -67,7 +67,7 @@ impl ItemNursery {
                 if !inserted {
                     return Err(syn::Error::new(
                         item.attr_name.span(),
-                        &format!("Duplicated #[py*] attribute found for {:?}", &item.py_names),
+                        format!("Duplicated #[py*] attribute found for {:?}", &item.py_names),
                     ));
                 }
             }
diff --git a/vm/src/stdlib/os.rs b/vm/src/stdlib/os.rs
index 6862ad0af..210cc3f82 100644
--- a/vm/src/stdlib/os.rs
+++ b/vm/src/stdlib/os.rs
@@ -1109,7 +1109,7 @@ pub(super) mod _os {
         // TODO: replicate CPython's win32_xstat
         let [] = dir_fd.0;
         let meta = match file {
-            PathOrFd::Path(path) => super::fs_metadata(&path, follow_symlinks.0)?,
+            PathOrFd::Path(path) => super::fs_metadata(path, follow_symlinks.0)?,
             PathOrFd::Fd(fno) => {
                 use std::os::windows::io::FromRawHandle;
                 let handle = Fd(fno).to_raw_handle()?;
@@ -1521,9 +1521,10 @@ pub(super) mod _os {
             };
 
             let tick_for_second = unsafe { libc::sysconf(libc::_SC_CLK_TCK) } as f64;
-            let c = unsafe { libc::times(&mut t as *mut _) } as i64;
+            let c = unsafe { libc::times(&mut t as *mut _) };
 
-            if c == -1 {
+            // XXX: The signedness of `clock_t` varies from platform to platform.
+            if c == (-1i8) as libc::clock_t {
                 return Err(vm.new_os_error("Fail to get times".to_string()));
             }
 
diff --git a/vm/src/stdlib/winreg.rs b/vm/src/stdlib/winreg.rs
index 17a430fd6..660df63da 100644
--- a/vm/src/stdlib/winreg.rs
+++ b/vm/src/stdlib/winreg.rs
@@ -258,7 +258,7 @@ mod winreg {
         value: PyStrRef,
         vm: &VirtualMachine,
     ) -> PyResult<()> {
-        if typ != REG_SZ as u32 {
+        if typ != REG_SZ {
             return Err(vm.new_type_error("type must be winreg.REG_SZ".to_owned()));
         }
         let subkey = subkey.as_ref().map_or("", |s| s.as_str());