diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index a2d2a4a..0bdde3a 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3786,7 +3786,7 @@
 			global
 			{not in Vi}
 			{only available when compiled with |+xim| and
-			|+GUI_GTK|}
+			|+GUI_GTK|}				*E599*
 	Specifies the key that your Input Method in X-Windows uses for
 	activation.  When this is specified correctly, vim can fully control
 	IM with 'imcmdline', 'iminsert' and 'imsearch'.