diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index d48ccd28..2d75d151 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -23,9 +23,19 @@ permissions:
   contents: read
 
 jobs:
-  build_x86_64:
-    name: "Build (x86_64/Linux)"
-    runs-on: ubuntu-latest
+  build:
+    strategy:
+      matrix:
+        include:
+          - host: "ubuntu-latest"
+            os: "linux"
+            arch: "x86_64"
+          - host: "macos-latest"
+            os: "macos"
+            arch: "aarch64"
+
+    name: "Build (${{ matrix.arch }}/${{ matrix.os }})"
+    runs-on: ${{ matrix.host }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -47,7 +57,7 @@ jobs:
       - name: "Upload binaries"
         uses: actions/upload-artifact@v4
         with:
-          name: binaries-x86_64-linux
+          name: binaries-${{ matrix.arch }}-${{ matrix.os }}
           path: target/release/brush
 
   build_cross:
diff --git a/Cargo.lock b/Cargo.lock
index 310eb18d..b007a5e7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -251,6 +251,7 @@ dependencies = [
  "async-trait",
  "brush-parser",
  "cached",
+ "cfg-if",
  "clap",
  "command-fds",
  "criterion",
diff --git a/brush-core/Cargo.toml b/brush-core/Cargo.toml
index 8da18790..f168fb43 100644
--- a/brush-core/Cargo.toml
+++ b/brush-core/Cargo.toml
@@ -21,6 +21,7 @@ async-recursion = "1.1.0"
 async-trait = "0.1.80"
 brush-parser = { version = "^0.2.3", path = "../brush-parser" }
 cached = "0.51.3"
+cfg-if = "1.0.0"
 # N.B. Pin to 4.4.18 for now to keep to 1.72.0 as MSRV; 4.5.x requires a later version.
 clap = { version = "=4.4.18", features = ["derive", "wrap_help"] }
 fancy-regex = "0.13.0"
@@ -57,9 +58,11 @@ whoami = "1.5.1"
 [target.'cfg(unix)'.dependencies]
 command-fds = "0.3.0"
 nix = { version = "0.29.0", features = ["fs", "process", "signal", "term", "user"] }
-procfs = "0.16.0"
 uzers = "0.12.0"
 
+[target.'cfg(target_os = "linux")'.dependencies]
+procfs = "0.16.0"
+
 [dev-dependencies]
 anyhow = "1.0.86"
 criterion = { version = "0.5.1", features = ["async_tokio", "html_reports"] }
diff --git a/brush-core/src/builtins/umask.rs b/brush-core/src/builtins/umask.rs
index 4c8aca0d..ad9dac48 100644
--- a/brush-core/src/builtins/umask.rs
+++ b/brush-core/src/builtins/umask.rs
@@ -1,5 +1,7 @@
 use crate::{builtin, commands, error};
+use cfg_if::cfg_if;
 use clap::Parser;
+use nix::sys::stat::Mode;
 use std::io::Write;
 
 /// Manage the process umask.
@@ -53,14 +55,25 @@ impl builtin::Command for UmaskCommand {
     }
 }
 
-fn get_umask() -> Result<u32, error::Error> {
-    let me = procfs::process::Process::myself()?;
-    let status = me.status()?;
-    status.umask.ok_or_else(|| error::Error::InvalidUmask)
+cfg_if! {
+    if #[cfg(target_os = "linux")] {
+        fn get_umask() -> Result<u32, error::Error> {
+            let me = procfs::process::Process::myself()?;
+            let status = me.status()?;
+            status.umask.ok_or_else(|| error::Error::InvalidUmask)
+        }
+    } else {
+        fn get_umask() -> Result<u32, error::Error> {
+            let u = nix::sys::stat::umask(Mode::empty());
+            nix::sys::stat::umask(u);
+            Ok(u.bits() as u32)
+        }
+    }
 }
 
 fn set_umask(value: u32) -> Result<(), error::Error> {
-    let mode = nix::sys::stat::Mode::from_bits(value).ok_or_else(|| error::Error::InvalidUmask)?;
+    let mode =
+        nix::sys::stat::Mode::from_bits(value as _).ok_or_else(|| error::Error::InvalidUmask)?;
     nix::sys::stat::umask(mode);
     Ok(())
 }
diff --git a/brush-core/src/error.rs b/brush-core/src/error.rs
index fd6ed79b..a1abbb9f 100644
--- a/brush-core/src/error.rs
+++ b/brush-core/src/error.rs
@@ -153,7 +153,7 @@ pub enum Error {
     InvalidUmask,
 
     /// An error occurred reading from procfs.
-    #[cfg(unix)]
+    #[cfg(target_os = "linux")]
     #[error("procfs error: {0}")]
     ProcfsError(#[from] procfs::ProcError),
 
diff --git a/brush-core/src/interp.rs b/brush-core/src/interp.rs
index 58fc755a..119076c7 100644
--- a/brush-core/src/interp.rs
+++ b/brush-core/src/interp.rs
@@ -2,7 +2,7 @@ use brush_parser::ast::{self, CommandPrefixOrSuffixItem};
 use itertools::Itertools;
 use std::collections::VecDeque;
 use std::io::Write;
-#[cfg(unix)]
+#[cfg(target_os = "linux")]
 use std::os::fd::{AsFd, AsRawFd};
 #[cfg(unix)]
 use std::os::unix::process::ExitStatusExt;
@@ -1469,7 +1469,7 @@ fn setup_open_file_with_contents(contents: &str) -> Result<OpenFile, error::Erro
     let bytes = contents.as_bytes();
     let len = i32::try_from(bytes.len())?;
 
-    #[cfg(unix)]
+    #[cfg(target_os = "linux")]
     nix::fcntl::fcntl(
         reader.as_fd().as_raw_fd(),
         nix::fcntl::FcntlArg::F_SETPIPE_SZ(len),