diff --git a/std/src/sys/pal/windows/c.rs b/std/src/sys/pal/windows/c.rs
index 83b87f47a8bec..9f189452ecc83 100644
--- a/std/src/sys/pal/windows/c.rs
+++ b/std/src/sys/pal/windows/c.rs
@@ -19,7 +19,6 @@ pub use windows_sys::*;
 
 pub type DWORD = c_ulong;
 pub type WCHAR = u16;
-pub type ULONG = c_ulong;
 
 pub type socklen_t = c_int;
 pub type ADDRESS_FAMILY = c_ushort;
@@ -252,9 +251,9 @@ pub unsafe fn NtReadFile(
     apccontext: *mut c_void,
     iostatusblock: &mut IO_STATUS_BLOCK,
     buffer: *mut crate::mem::MaybeUninit<u8>,
-    length: ULONG,
+    length: u32,
     byteoffset: Option<&i64>,
-    key: Option<&ULONG>,
+    key: Option<&u32>,
 ) -> NTSTATUS {
     windows_sys::NtReadFile(
         filehandle.as_raw_handle(),
@@ -275,9 +274,9 @@ pub unsafe fn NtWriteFile(
     apccontext: *mut c_void,
     iostatusblock: &mut IO_STATUS_BLOCK,
     buffer: *const u8,
-    length: ULONG,
+    length: u32,
     byteoffset: Option<&i64>,
-    key: Option<&ULONG>,
+    key: Option<&u32>,
 ) -> NTSTATUS {
     windows_sys::NtWriteFile(
         filehandle.as_raw_handle(),
diff --git a/std/src/sys/pal/windows/io.rs b/std/src/sys/pal/windows/io.rs
index 77b8f3c410eb8..1d0707926c923 100644
--- a/std/src/sys/pal/windows/io.rs
+++ b/std/src/sys/pal/windows/io.rs
@@ -15,9 +15,9 @@ pub struct IoSlice<'a> {
 impl<'a> IoSlice<'a> {
     #[inline]
     pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
-        assert!(buf.len() <= c::ULONG::MAX as usize);
+        assert!(buf.len() <= u32::MAX as usize);
         IoSlice {
-            vec: c::WSABUF { len: buf.len() as c::ULONG, buf: buf.as_ptr() as *mut u8 },
+            vec: c::WSABUF { len: buf.len() as u32, buf: buf.as_ptr() as *mut u8 },
             _p: PhantomData,
         }
     }
@@ -29,7 +29,7 @@ impl<'a> IoSlice<'a> {
         }
 
         unsafe {
-            self.vec.len -= n as c::ULONG;
+            self.vec.len -= n as u32;
             self.vec.buf = self.vec.buf.add(n);
         }
     }
@@ -49,9 +49,9 @@ pub struct IoSliceMut<'a> {
 impl<'a> IoSliceMut<'a> {
     #[inline]
     pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
-        assert!(buf.len() <= c::ULONG::MAX as usize);
+        assert!(buf.len() <= u32::MAX as usize);
         IoSliceMut {
-            vec: c::WSABUF { len: buf.len() as c::ULONG, buf: buf.as_mut_ptr() },
+            vec: c::WSABUF { len: buf.len() as u32, buf: buf.as_mut_ptr() },
             _p: PhantomData,
         }
     }
@@ -63,7 +63,7 @@ impl<'a> IoSliceMut<'a> {
         }
 
         unsafe {
-            self.vec.len -= n as c::ULONG;
+            self.vec.len -= n as u32;
             self.vec.buf = self.vec.buf.add(n);
         }
     }
diff --git a/std/src/sys/pal/windows/rand.rs b/std/src/sys/pal/windows/rand.rs
index 09f527a09bf12..e366bb995626a 100644
--- a/std/src/sys/pal/windows/rand.rs
+++ b/std/src/sys/pal/windows/rand.rs
@@ -20,7 +20,7 @@ pub fn hashmap_random_keys() -> (u64, u64) {
 
     let mut v = (0, 0);
     let ret = unsafe {
-        c::RtlGenRandom(ptr::addr_of_mut!(v).cast::<c_void>(), mem::size_of_val(&v) as c::ULONG)
+        c::RtlGenRandom(ptr::addr_of_mut!(v).cast::<c_void>(), mem::size_of_val(&v) as u32)
     };
 
     if ret != 0 { v } else { panic!("RNG broken: {}", io::Error::last_os_error()) }
diff --git a/std/src/sys/pal/windows/stdio.rs b/std/src/sys/pal/windows/stdio.rs
index 07686ab293339..831efb252c472 100644
--- a/std/src/sys/pal/windows/stdio.rs
+++ b/std/src/sys/pal/windows/stdio.rs
@@ -341,9 +341,9 @@ fn read_u16s(handle: c::HANDLE, buf: &mut [MaybeUninit<u16>]) -> io::Result<usiz
     // traditional DOS method to indicate end of character stream / user input (SUB).
     // See #38274 and https://stackoverflow.com/questions/43836040/win-api-readconsole.
     const CTRL_Z: u16 = 0x1A;
-    const CTRL_Z_MASK: c::ULONG = 1 << CTRL_Z;
+    const CTRL_Z_MASK: u32 = 1 << CTRL_Z;
     let input_control = c::CONSOLE_READCONSOLE_CONTROL {
-        nLength: crate::mem::size_of::<c::CONSOLE_READCONSOLE_CONTROL>() as c::ULONG,
+        nLength: crate::mem::size_of::<c::CONSOLE_READCONSOLE_CONTROL>() as u32,
         nInitialChars: 0,
         dwCtrlWakeupMask: CTRL_Z_MASK,
         dwControlKeyState: 0,