diff --git a/zdiff.1 b/zdiff.1
-index 588974c..3a586a2 100644
+index 588974c..3b0ace5 100644
--- a/zdiff.1
+++ b/zdiff.1
@@ -10,6 +10,7 @@ zcmp, zdiff \- compare compressed files
.I cmp
or
.IR diff "."
-@@ -36,6 +37,13 @@ The exit status from
- or
- .I diff
- is preserved.
-+.P
-+When both files must be uncompressed before comparison, the second is
-+uncompressed to
-+.IR "/tmp" "."
-+In all other cases,
-+.IR "zdiff" " and " "zcmp"
-+use only a pipe.
- .SH "SEE ALSO"
- cmp(1), diff(1), zmore(1), zgrep(1), znew(1), zforce(1), gzip(1), gzexe(1)
- .SH BUGS