diff --git a/build.rs b/build.rs
index d5d1af7..6752846 100644
--- a/build.rs
+++ b/build.rs
@@ -10,6 +10,9 @@ fn main() {
         }
     };
 
+    if !cfg.probe_rustc_version(1, 62) {
+        autocfg::emit("async_process_no_windows_raw_arg");
+    }
     if !cfg.probe_rustc_version(1, 63) {
         autocfg::emit("async_process_no_io_safety");
     }
diff --git a/src/lib.rs b/src/lib.rs
index e7b3b51..9f2bb6a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -82,6 +82,10 @@ pub mod unix;
 #[cfg(windows)]
 pub mod windows;
 
+mod sealed {
+    pub trait Sealed {}
+}
+
 /// An event delivered every time the SIGCHLD signal occurs.
 static SIGCHLD: Event = Event::new();
 
@@ -516,6 +520,7 @@ impl AsRawFd for ChildStdin {
     }
 }
 
+/// **Note:** This implementation is only available on Rust 1.63+.
 #[cfg(all(not(async_process_no_io_safety), unix))]
 impl AsFd for ChildStdin {
     fn as_fd(&self) -> BorrowedFd<'_> {
@@ -523,6 +528,7 @@ impl AsFd for ChildStdin {
     }
 }
 
+/// **Note:** This implementation is only available on Rust 1.63+.
 #[cfg(all(not(async_process_no_io_safety), unix))]
 impl TryFrom<ChildStdin> for OwnedFd {
     type Error = io::Error;
@@ -600,6 +606,7 @@ impl AsRawFd for ChildStdout {
     }
 }
 
+/// **Note:** This implementation is only available on Rust 1.63+.
 #[cfg(all(not(async_process_no_io_safety), unix))]
 impl AsFd for ChildStdout {
     fn as_fd(&self) -> BorrowedFd<'_> {
@@ -607,6 +614,7 @@ impl AsFd for ChildStdout {
     }
 }
 
+/// **Note:** This implementation is only available on Rust 1.63+.
 #[cfg(all(not(async_process_no_io_safety), unix))]
 impl TryFrom<ChildStdout> for OwnedFd {
     type Error = io::Error;
@@ -673,6 +681,7 @@ impl AsRawFd for ChildStderr {
     }
 }
 
+/// **Note:** This implementation is only available on Rust 1.63+.
 #[cfg(all(not(async_process_no_io_safety), unix))]
 impl AsFd for ChildStderr {
     fn as_fd(&self) -> BorrowedFd<'_> {
@@ -680,6 +689,7 @@ impl AsFd for ChildStderr {
     }
 }
 
+/// **Note:** This implementation is only available on Rust 1.63+.
 #[cfg(all(not(async_process_no_io_safety), unix))]
 impl TryFrom<ChildStderr> for OwnedFd {
     type Error = io::Error;
diff --git a/src/unix.rs b/src/unix.rs
index 4208ecf..034f881 100644
--- a/src/unix.rs
+++ b/src/unix.rs
@@ -7,7 +7,10 @@ use std::os::unix::process::CommandExt as _;
 use crate::Command;
 
 /// Unix-specific extensions to the [`Command`] builder.
-pub trait CommandExt {
+///
+/// This trait is sealed: it cannot be implemented outside `async-process`.
+/// This is so that future additional methods are not breaking changes.
+pub trait CommandExt: crate::sealed::Sealed {
     /// Sets the child process's user ID. This translates to a
     /// `setuid` call in the child process. Failure in the `setuid`
     /// call will cause the spawn to fail.
@@ -88,6 +91,7 @@ pub trait CommandExt {
         S: AsRef<OsStr>;
 }
 
+impl crate::sealed::Sealed for Command {}
 impl CommandExt for Command {
     fn uid(&mut self, id: u32) -> &mut Command {
         self.inner.uid(id);
diff --git a/src/windows.rs b/src/windows.rs
index 64c042c..453d3a5 100644
--- a/src/windows.rs
+++ b/src/windows.rs
@@ -1,25 +1,46 @@
 //! Windows-specific extensions.
 
+#[cfg(not(async_process_no_windows_raw_arg))]
+use std::ffi::OsStr;
 use std::os::windows::io::{AsRawHandle, RawHandle};
 use std::os::windows::process::CommandExt as _;
 
 use crate::{Child, Command};
 
 /// Windows-specific extensions to the [`Command`] builder.
-pub trait CommandExt {
+///
+/// This trait is sealed: it cannot be implemented outside `async-process`.
+/// This is so that future additional methods are not breaking changes.
+pub trait CommandExt: crate::sealed::Sealed {
     /// Sets the [process creation flags][1] to be passed to `CreateProcess`.
     ///
     /// These will always be ORed with `CREATE_UNICODE_ENVIRONMENT`.
     ///
     /// [1]: https://docs.microsoft.com/en-us/windows/win32/procthread/process-creation-flags
     fn creation_flags(&mut self, flags: u32) -> &mut Command;
+
+    /// Append literal text to the command line without any quoting or escaping.
+    ///
+    /// This is useful for passing arguments to `cmd.exe /c`, which doesn't follow
+    /// `CommandLineToArgvW` escaping rules.
+    ///
+    /// **Note:** This method is only available on Rust 1.62+.
+    #[cfg(not(async_process_no_windows_raw_arg))]
+    fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut Command;
 }
 
+impl crate::sealed::Sealed for Command {}
 impl CommandExt for Command {
     fn creation_flags(&mut self, flags: u32) -> &mut Command {
         self.inner.creation_flags(flags);
         self
     }
+
+    #[cfg(not(async_process_no_windows_raw_arg))]
+    fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut Command {
+        self.inner.raw_arg(text_to_append_as_is);
+        self
+    }
 }
 
 impl AsRawHandle for Child {