When pressing AltGr in XEmacs 21.4.1[56] on my Fedora Core 3 box (Mule, Finnish X keymap, x.org X11 6.8.1), an error is signaled: iso-level3-shift is not defined Additionally, pressing AltGr quits I-search, which is very annoying. GNU Emacs suffers from the same I-search problem, but does not display any errors. I Googled and found some workaround suggestions like: (define-key global-map [(iso-level3-shift)] '#ignore) This "works" in the sense that the error message goes away; however it does not help with the I-search problem which is the important one. But when discussing this in Red Hat Bugzilla, these were found: Apparent root cause: https://bugs.freedesktop.org/show_bug.cgi?id=1625 The workaround applied in GNU Emacs: http://lists.gnu.org/archive/html/bug-gnu-emacs/2004-10/msg00150.html Attached is a workaround patch for XEmacs 21.4.16 which fixes the problem for me (probably applicable to 21.5 too). Could someone review whether this patch is worth applying in XEmacs? Or maybe <X11/keysym.h> should be included in xintrinsic.h before <X11/Intrinsic.h> instead for completeness?