diff --git a/tokio/Cargo.toml b/tokio/Cargo.toml
index e074fa190..9b512694e 100644
--- a/tokio/Cargo.toml
+++ b/tokio/Cargo.toml
@@ -134,9 +134,6 @@ features = [
     "Win32_Security_Authorization",
 ]
 
-[target.'cfg(windows)'.dev-dependencies.ntapi]
-version = "0.3.6"
-
 [dev-dependencies]
 tokio-test = { version = "0.4.0", path = "../tokio-test" }
 tokio-stream = { version = "0.1", path = "../tokio-stream" }
diff --git a/tokio/tests/net_named_pipe.rs b/tokio/tests/net_named_pipe.rs
index 02c8a0919..02eda48e5 100644
--- a/tokio/tests/net_named_pipe.rs
+++ b/tokio/tests/net_named_pipe.rs
@@ -2,13 +2,11 @@
 #![cfg(all(windows))]
 
 use std::io;
-use std::mem;
-use std::os::windows::io::AsRawHandle;
 use std::time::Duration;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::windows::named_pipe::{ClientOptions, PipeMode, ServerOptions};
 use tokio::time;
-use windows_sys::Win32::Foundation::{ERROR_NO_DATA, ERROR_PIPE_BUSY, NO_ERROR, UNICODE_STRING};
+use windows_sys::Win32::Foundation::{ERROR_NO_DATA, ERROR_PIPE_BUSY};
 
 #[tokio::test]
 async fn test_named_pipe_client_drop() -> io::Result<()> {
@@ -16,8 +14,6 @@ async fn test_named_pipe_client_drop() -> io::Result<()> {
 
     let mut server = ServerOptions::new().create(PIPE_NAME)?;
 
-    assert_eq!(num_instances("test-named-pipe-client-drop")?, 1);
-
     let client = ClientOptions::new().open(PIPE_NAME)?;
 
     server.connect().await?;
@@ -401,53 +397,3 @@ async fn test_named_pipe_access() -> io::Result<()> {
     }
     Ok(())
 }
-
-fn num_instances(pipe_name: impl AsRef<str>) -> io::Result<u32> {
-    use ntapi::ntioapi;
-
-    let mut name = pipe_name.as_ref().encode_utf16().collect::<Vec<_>>();
-    let mut name = UNICODE_STRING {
-        Length: (name.len() * mem::size_of::<u16>()) as u16,
-        MaximumLength: (name.len() * mem::size_of::<u16>()) as u16,
-        Buffer: name.as_mut_ptr(),
-    };
-    let root = std::fs::File::open(r"\\.\Pipe\")?;
-    let mut io_status_block = unsafe { mem::zeroed() };
-    let mut file_directory_information = [0_u8; 1024];
-
-    let status = unsafe {
-        ntioapi::NtQueryDirectoryFile(
-            root.as_raw_handle().cast(),
-            std::ptr::null_mut(),
-            None,
-            std::ptr::null_mut(),
-            &mut io_status_block,
-            &mut file_directory_information as *mut _ as *mut _,
-            1024,
-            ntioapi::FileDirectoryInformation,
-            0,
-            &mut name as *mut _ as _,
-            0,
-        )
-    };
-
-    if status as u32 != NO_ERROR {
-        return Err(io::Error::last_os_error());
-    }
-
-    let info = unsafe {
-        mem::transmute::<_, &ntioapi::FILE_DIRECTORY_INFORMATION>(&file_directory_information)
-    };
-    let raw_name = unsafe {
-        std::slice::from_raw_parts(
-            info.FileName.as_ptr(),
-            info.FileNameLength as usize / mem::size_of::<u16>(),
-        )
-    };
-    let name = String::from_utf16(raw_name).unwrap();
-    let num_instances = unsafe { *info.EndOfFile.QuadPart() };
-
-    assert_eq!(name, pipe_name.as_ref());
-
-    Ok(num_instances as u32)
-}