diff --git a/twander.1 b/twander.1
index d331ee3..85ed318 100644
--- a/twander.1
+++ b/twander.1
@@ -3,7 +3,7 @@
 Wander around a filesystem executing commands of your choice on selected
 files.
 .SH SYNOPSIS
-twander [-bcfhnqrswvxy] [startdir]
+twander [-bcdfhnqrswvxy] [startdir]
 .SH DESCRIPTION
 \'twander\' is a GUI-based file tree navigation tool.  It lets you "wander"
 through your file system at will.  Unlike other similar programs,
@@ -28,6 +28,18 @@
 file. (default is ~/.twander)
 
 .TP
+.B -d
+Start in debug mode.  The program runs, but does not actually execute
+any commands.  Instead, the contents of various internal tables such
+as the Symbol Table and Command Table are listed on standard output.
+If the user presses a defined command key, the command that would have
+been executed is printed to standard output, but no command is
+actually performed.  This option is mildly useful in debugging
+configuration files insfar as it will display the command string after
+all substitutions of variables (both builtins and user-defined) has
+been done.
+
+.TP
 .B -f forecolor
 Desired foreground color. (default: green)