diff --git a/docs/latex/wx/panel.tex b/docs/latex/wx/panel.tex
index 6dfeb8fe6e..63b331c13f 100644
--- a/docs/latex/wx/panel.tex
+++ b/docs/latex/wx/panel.tex
@@ -43,7 +43,7 @@ A panel may be loaded from a wxWindows resource file (extension {\tt wxr}).
 
 Default constructor.
 
-\func{}{wxPanel}{\param{wxWindow* }{parent}, \param{wxWindowID }{id},\rtfsp
+\func{}{wxPanel}{\param{wxWindow* }{parent}, \param{wxWindowID }{id = $-1$},\rtfsp
 \param{const wxPoint\& }{pos = wxDefaultPosition},\rtfsp
 \param{const wxSize\& }{size = wxDefaultSize},\rtfsp
 \param{long}{ style = wxTAB\_TRAVERSAL},\rtfsp