diff --git a/internal/command/command_native.go b/internal/command/command_native.go
index 14850918a..086237fa2 100644
--- a/internal/command/command_native.go
+++ b/internal/command/command_native.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"os"
 	"os/exec"
-	"syscall"
 
 	"github.com/pkg/errors"
 	"go.uber.org/zap"
@@ -69,11 +68,11 @@ func (c *NativeCommand) Start(ctx context.Context) (err error) {
 
 	if f, ok := stdin.(*os.File); ok && f != nil {
 		// Duplicate /dev/stdin.
-		newStdinFd, err := dup(int(f.Fd()))
+		newStdinFd, err := dup(f.Fd())
 		if err != nil {
 			return errors.Wrap(err, "failed to dup stdin")
 		}
-		syscall.CloseOnExec(newStdinFd)
+		closeOnExec(newStdinFd)
 
 		// Setting stdin to the non-block mode fails on the simple "read" command.
 		// On the other hand, it allows to use SetReadDeadline().
diff --git a/internal/command/command_native_test.go b/internal/command/command_native_test.go
index e03a42306..fbd832409 100644
--- a/internal/command/command_native_test.go
+++ b/internal/command/command_native_test.go
@@ -1,3 +1,5 @@
+//go:build !windows
+
 package command
 
 import (
diff --git a/internal/command/command_test.go b/internal/command/command_test.go
index 9261a5b1d..07cf4782f 100644
--- a/internal/command/command_test.go
+++ b/internal/command/command_test.go
@@ -1,3 +1,5 @@
+//go:build !windows
+
 package command
 
 import (
diff --git a/internal/command/command_unix.go b/internal/command/command_unix.go
index 4da20d0b0..b8be2ded9 100644
--- a/internal/command/command_unix.go
+++ b/internal/command/command_unix.go
@@ -30,8 +30,16 @@ func disableEcho(fd uintptr) error {
 	return errors.Wrap(err, "failed to set tty attr")
 }
 
-func dup(fd int) (int, error) {
-	return syscall.Dup(fd)
+func dup(fd uintptr) (uintptr, error) {
+	dupFd, err := syscall.Dup(int(fd))
+	if err != nil {
+		return 0, err
+	}
+	return uintptr(dupFd), nil
+}
+
+func closeOnExec(fd uintptr) {
+	syscall.CloseOnExec(int(fd))
 }
 
 // func setSysProcAttrPgid(cmd *exec.Cmd) {
diff --git a/internal/command/command_virtual_test.go b/internal/command/command_virtual_test.go
index 4217e0ee6..aba60b458 100644
--- a/internal/command/command_virtual_test.go
+++ b/internal/command/command_virtual_test.go
@@ -1,3 +1,5 @@
+//go:build !windows
+
 package command
 
 import (
diff --git a/internal/command/command_windows.go b/internal/command/command_windows.go
index 8dd6be163..1fb1ebcd7 100644
--- a/internal/command/command_windows.go
+++ b/internal/command/command_windows.go
@@ -1,6 +1,6 @@
 //go:build windows
 
-package runner
+package command
 
 import (
 	"os"
@@ -13,10 +13,14 @@ func setSysProcAttrCtty(cmd *exec.Cmd) {}
 
 func setSysProcAttrPgid(cmd *exec.Cmd) {}
 
-func dup(fd int) (int, error) {
+func dup(fd uintptr) (uintptr, error) {
 	return fd, nil
 }
 
+func closeOnExec(uintptr) {
+	// noop
+}
+
 func disableEcho(fd uintptr) error {
 	return errors.New("Error: Environment not supported! " +
 		"Runme currently doesn't support PowerShell. " +