diff --git a/color_windows.go b/color_windows.go
index 32eb9e0..f9a68c3 100644
--- a/color_windows.go
+++ b/color_windows.go
@@ -33,6 +33,7 @@ func selectColor(opts options) (color.Color, error) {
 
 	var args _CHOOSECOLOR
 	args.StructSize = uint32(unsafe.Sizeof(args))
+	args.Owner, _ = opts.attach.(uintptr)
 	args.CustColors = &customColors
 
 	if opts.color != nil {
diff --git a/date_windows.go b/date_windows.go
index 4748739..82ee7b6 100644
--- a/date_windows.go
+++ b/date_windows.go
@@ -56,11 +56,12 @@ func (dlg *calendarDialog) setup(text string, opts options) (time.Time, error) {
 	}
 	defer unregisterClass.Call(cls, instance)
 
+	owner, _ := opts.attach.(uintptr)
 	dlg.wnd, _, _ = createWindowEx.Call(_WS_EX_CONTROLPARENT|_WS_EX_WINDOWEDGE|_WS_EX_DLGMODALFRAME,
 		cls, strptr(*opts.title),
 		_WS_POPUPWINDOW|_WS_CLIPSIBLINGS|_WS_DLGFRAME,
 		_CW_USEDEFAULT, _CW_USEDEFAULT,
-		281, 281, 0, 0, instance, uintptr(unsafe.Pointer(dlg)))
+		281, 281, owner, 0, instance, uintptr(unsafe.Pointer(dlg)))
 
 	dlg.textCtl, _, _ = createWindowEx.Call(0,
 		strptr("STATIC"), strptr(text),
diff --git a/entry_windows.go b/entry_windows.go
index 0038cfa..216bd63 100644
--- a/entry_windows.go
+++ b/entry_windows.go
@@ -55,11 +55,12 @@ func (dlg *entryDialog) setup(text string, opts options) (string, error) {
 	}
 	defer unregisterClass.Call(cls, instance)
 
+	owner, _ := opts.attach.(uintptr)
 	dlg.wnd, _, _ = createWindowEx.Call(_WS_EX_CONTROLPARENT|_WS_EX_WINDOWEDGE|_WS_EX_DLGMODALFRAME,
 		cls, strptr(*opts.title),
 		_WS_POPUPWINDOW|_WS_CLIPSIBLINGS|_WS_DLGFRAME,
 		_CW_USEDEFAULT, _CW_USEDEFAULT,
-		281, 141, 0, 0, instance, uintptr(unsafe.Pointer(dlg)))
+		281, 141, owner, 0, instance, uintptr(unsafe.Pointer(dlg)))
 
 	dlg.textCtl, _, _ = createWindowEx.Call(0,
 		strptr("STATIC"), strptr(text),
diff --git a/file_windows.go b/file_windows.go
index e0a2b90..ca90e2c 100644
--- a/file_windows.go
+++ b/file_windows.go
@@ -43,6 +43,7 @@ func selectFile(opts options) (string, error) {
 
 	var args _OPENFILENAME
 	args.StructSize = uint32(unsafe.Sizeof(args))
+	args.Owner, _ = opts.attach.(uintptr)
 	args.Flags = _OFN_NOCHANGEDIR | _OFN_FILEMUSTEXIST | _OFN_EXPLORER
 
 	if opts.title != nil {
@@ -88,6 +89,7 @@ func selectFileMultiple(opts options) ([]string, error) {
 
 	var args _OPENFILENAME
 	args.StructSize = uint32(unsafe.Sizeof(args))
+	args.Owner, _ = opts.attach.(uintptr)
 	args.Flags = _OFN_NOCHANGEDIR | _OFN_ALLOWMULTISELECT | _OFN_FILEMUSTEXIST | _OFN_EXPLORER
 
 	if opts.title != nil {
@@ -158,6 +160,7 @@ func selectFileSave(opts options) (string, error) {
 
 	var args _OPENFILENAME
 	args.StructSize = uint32(unsafe.Sizeof(args))
+	args.Owner, _ = opts.attach.(uintptr)
 	args.Flags = _OFN_NOCHANGEDIR | _OFN_PATHMUSTEXIST | _OFN_NOREADONLYRETURN | _OFN_EXPLORER
 
 	if opts.title != nil {
@@ -268,7 +271,8 @@ func pickFolders(opts options, multi bool) (str string, lst []string, err error)
 		defer unhook()
 	}
 
-	hr, _, _ = dialog.Call(dialog.Show, 0)
+	owner, _ := opts.attach.(uintptr)
+	hr, _, _ = dialog.Call(dialog.Show, owner)
 	if opts.ctx != nil && opts.ctx.Err() != nil {
 		return "", nil, opts.ctx.Err()
 	}
@@ -328,6 +332,7 @@ func pickFolders(opts options, multi bool) (str string, lst []string, err error)
 
 func browseForFolder(opts options) (string, []string, error) {
 	var args _BROWSEINFO
+	args.Owner, _ = opts.attach.(uintptr)
 	args.Flags = 0x1 // BIF_RETURNONLYFSDIRS
 
 	if opts.title != nil {
diff --git a/list_windows.go b/list_windows.go
index fc2cdeb..f2e0934 100644
--- a/list_windows.go
+++ b/list_windows.go
@@ -72,11 +72,12 @@ func (dlg *listDialog) setup(text string, opts options) ([]string, error) {
 	}
 	defer unregisterClass.Call(cls, instance)
 
+	owner, _ := opts.attach.(uintptr)
 	dlg.wnd, _, _ = createWindowEx.Call(_WS_EX_CONTROLPARENT|_WS_EX_WINDOWEDGE|_WS_EX_DLGMODALFRAME,
 		cls, strptr(*opts.title),
 		_WS_POPUPWINDOW|_WS_CLIPSIBLINGS|_WS_DLGFRAME,
 		_CW_USEDEFAULT, _CW_USEDEFAULT,
-		281, 281, 0, 0, instance, uintptr(unsafe.Pointer(dlg)))
+		281, 281, owner, 0, instance, uintptr(unsafe.Pointer(dlg)))
 
 	dlg.textCtl, _, _ = createWindowEx.Call(0,
 		strptr("STATIC"), strptr(text),
diff --git a/msg_windows.go b/msg_windows.go
index def918d..c1084c4 100644
--- a/msg_windows.go
+++ b/msg_windows.go
@@ -70,7 +70,8 @@ func message(kind messageKind, text string, opts options) error {
 		title = syscall.StringToUTF16Ptr(*opts.title)
 	}
 
-	s, _, err := messageBox.Call(0, strptr(text), uintptr(unsafe.Pointer(title)), flags)
+	owner, _ := opts.attach.(uintptr)
+	s, _, err := messageBox.Call(owner, strptr(text), uintptr(unsafe.Pointer(title)), flags)
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {
 		return opts.ctx.Err()
diff --git a/progress_windows.go b/progress_windows.go
index f2aa241..df47739 100644
--- a/progress_windows.go
+++ b/progress_windows.go
@@ -135,11 +135,12 @@ func (dlg *progressDialog) setup(opts options) error {
 	}
 	defer unregisterClass.Call(cls, instance)
 
+	owner, _ := opts.attach.(uintptr)
 	dlg.wnd, _, _ = createWindowEx.Call(_WS_EX_CONTROLPARENT|_WS_EX_WINDOWEDGE|_WS_EX_DLGMODALFRAME,
 		cls, strptr(*opts.title),
 		_WS_POPUPWINDOW|_WS_CLIPSIBLINGS|_WS_DLGFRAME,
 		_CW_USEDEFAULT, _CW_USEDEFAULT,
-		281, 133, 0, 0, instance, uintptr(unsafe.Pointer(dlg)))
+		281, 133, owner, 0, instance, uintptr(unsafe.Pointer(dlg)))
 
 	dlg.textCtl, _, _ = createWindowEx.Call(0,
 		strptr("STATIC"), 0,
diff --git a/pwd_windows.go b/pwd_windows.go
index 9f85423..6698f60 100644
--- a/pwd_windows.go
+++ b/pwd_windows.go
@@ -65,11 +65,12 @@ func (dlg *passwordDialog) setup(opts options) (string, string, error) {
 	}
 	defer unregisterClass.Call(cls, instance)
 
+	owner, _ := opts.attach.(uintptr)
 	dlg.wnd, _, _ = createWindowEx.Call(_WS_EX_CONTROLPARENT|_WS_EX_WINDOWEDGE|_WS_EX_DLGMODALFRAME,
 		cls, strptr(*opts.title),
 		_WS_POPUPWINDOW|_WS_CLIPSIBLINGS|_WS_DLGFRAME,
 		_CW_USEDEFAULT, _CW_USEDEFAULT,
-		281, 191, 0, 0, instance, uintptr(unsafe.Pointer(dlg)))
+		281, 191, owner, 0, instance, uintptr(unsafe.Pointer(dlg)))
 
 	dlg.uTextCtl, _, _ = createWindowEx.Call(0,
 		strptr("STATIC"), strptr("Username:"),
diff --git a/util_unix.go b/util_unix.go
index fe6c168..111cd47 100644
--- a/util_unix.go
+++ b/util_unix.go
@@ -4,7 +4,6 @@ package zenity
 
 import (
 	"bytes"
-	"fmt"
 	"os/exec"
 	"strconv"
 	"strings"
@@ -16,8 +15,8 @@ func appendGeneral(args []string, opts options) []string {
 	if opts.title != nil {
 		args = append(args, "--title", *opts.title)
 	}
-	if opts.attach != nil {
-		args = append(args, "--attach", fmt.Sprint(opts.attach))
+	if id, ok := opts.attach.(int); ok {
+		args = append(args, "--attach", strconv.Itoa(id))
 	}
 	if opts.modal {
 		args = append(args, "--modal")
diff --git a/zenity.go b/zenity.go
index b37a095..1a8dbf6 100644
--- a/zenity.go
+++ b/zenity.go
@@ -214,7 +214,9 @@ func Attach(id any) Option {
 		}
 
 	default:
-		if _, ok := id.(int); !ok {
+		switch id.(type) {
+		case int:
+		default:
 			panic("interface conversion: expected int")
 		}
 	}