diff --git a/src/unix/pty.cc b/src/unix/pty.cc
index 3b7d3dc1c..01fb67fce 100644
--- a/src/unix/pty.cc
+++ b/src/unix/pty.cc
@@ -112,8 +112,6 @@ struct ExitEvent {
   int exit_code = 0, signal_code = 0;
 };
 
-#if defined(__linux__)
-
 static int
 SetCloseOnExec(int fd) {
   int flags = fcntl(fd, F_GETFD, 0);
@@ -124,6 +122,8 @@ SetCloseOnExec(int fd) {
   return fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
 }
 
+#if defined(__linux__)
+
 /**
  * Close all file descriptors >= 3 to prevent FD leakage to child processes.
  * Uses close_range() syscall on Linux 5.9+, falls back to /proc/self/fd iteration.
@@ -415,6 +415,9 @@ Napi::Value PtyFork(const Napi::CallbackInfo& info) {
   if (pty_nonblock(master) == -1) {
     throw Napi::Error::New(napiEnv, "Could not set master fd to nonblocking.");
   }
+  if (SetCloseOnExec(master) == -1) {
+    throw Napi::Error::New(napiEnv, "Could not set master fd to close-on-exec.");
+  }
 #else
   int argc = argv_.Length();
   int argl = argc + 2;
@@ -488,6 +491,9 @@ Napi::Value PtyFork(const Napi::CallbackInfo& info) {
       if (pty_nonblock(master) == -1) {
         throw Napi::Error::New(napiEnv, "Could not set master fd to nonblocking.");
       }
+      if (SetCloseOnExec(master) == -1) {
+        throw Napi::Error::New(napiEnv, "Could not set master fd to close-on-exec.");
+      }
   }
 #endif
 
@@ -535,6 +541,10 @@ Napi::Value PtyOpen(const Napi::CallbackInfo& info) {
     throw Napi::Error::New(env, "Could not set slave fd to nonblocking.");
   }
 
+  if (SetCloseOnExec(master) == -1 || SetCloseOnExec(slave) == -1) {
+    throw Napi::Error::New(env, "Could not set pty fds to close-on-exec.");
+  }
+
   Napi::Object obj = Napi::Object::New(env);
   obj.Set("master", Napi::Number::New(env, master));
   obj.Set("slave", Napi::Number::New(env, slave));
diff --git a/src/unixTerminal.test.ts b/src/unixTerminal.test.ts
index a666e91aa..4abbd243d 100644
--- a/src/unixTerminal.test.ts
+++ b/src/unixTerminal.test.ts
@@ -112,6 +112,14 @@ if (process.platform !== 'win32') {
         term.slave!.write('slave\n');
         term.master!.write('master\n');
       });
+      if (process.platform === 'linux') {
+        it('should not leak the master or slave fd to processes the host spawns', () => {
+          term = UnixTerminal.open({});
+          const fds = cp.execFileSync('/bin/sh', ['-c', 'ls -l /proc/$$/fd'], { stdio: ['ignore', 'pipe', 'ignore'] }).toString();
+          assert.ok(!fds.includes('ptmx'), `child holds a pty master:\n${fds}`);
+          assert.ok(!fds.includes(term.ptsName), `child holds the pty slave ${term.ptsName}:\n${fds}`);
+        });
+      }
     });
     describe('close', () => {
       const term = new UnixTerminal('node');
@@ -287,6 +295,20 @@ if (process.platform !== 'win32') {
             done();
           }, 1000);
         });
+        it('should not leak pty master fds to processes the host spawns', () => {
+          const ptys: UnixTerminalType[] = [];
+          for (let i = 0; i < 2; i++) {
+            ptys.push(new UnixTerminal('/bin/bash', [], {}));
+          }
+          try {
+            const fds = cp.execFileSync('/bin/sh', ['-c', 'ls -l /proc/$$/fd'], { stdio: ['ignore', 'pipe', 'ignore'] }).toString();
+            assert.ok(!fds.includes('ptmx'), `child holds a pty master:\n${fds}`);
+          } finally {
+            for (const pty of ptys) {
+              pty.kill();
+            }
+          }
+        });
       }
       if (process.platform === 'darwin') {
         it('should return the name of the process', (done) => {