diff --git a/winsup/doc/cygwinenv.xml b/winsup/doc/cygwinenv.xml
index f549fee0d..a52b6ac19 100644
--- a/winsup/doc/cygwinenv.xml
+++ b/winsup/doc/cygwinenv.xml
@@ -28,9 +28,13 @@ Defaults to off.
which is useful for debugging. Win32filepath is
usually set to the path to gdb or
dumper, for example
-C:\cygwin\bin\gdb.exe.
+C:\cygwin\bin\gdb.exe.
There is no default set.
+
+The filename of the executing program and it's Windows process id are appended
+to the command as arguments.
+