diff --git a/file_windows.go b/file_windows.go
index 5a7d70a..1b56b00 100644
--- a/file_windows.go
+++ b/file_windows.go
@@ -239,7 +239,7 @@ func pickFolders(opts options, multi bool) (str string, lst []string, err error)
 			_IID_IShellItem,
 			uintptr(unsafe.Pointer(&item)))
 
-		if hr >= 0 && item != nil {
+		if int32(hr) >= 0 && item != nil {
 			dialog.Call(dialog.vtbl.SetFolder, uintptr(unsafe.Pointer(item)))
 			item.Call(item.vtbl.Release)
 		}
diff --git a/msg.go b/msg.go
index 7401db8..d054c9f 100644
--- a/msg.go
+++ b/msg.go
@@ -2,7 +2,7 @@ package zenity
 
 // ErrExtraButton is returned by dialog functions when the extra button is
 // pressed.
-const ErrExtraButton = stringErr("Extra button pressed")
+const ErrExtraButton = stringErr("extra button pressed")
 
 // Question displays the question dialog.
 //