diff --git a/man8/zic.8 b/man8/zic.8
index 3f8141a7a..90b4b9d51 100644
--- a/man8/zic.8
+++ b/man8/zic.8
@@ -228,7 +228,7 @@ or that starts with
 .RE
 .SH FILES
 Input files use the format described in this section; output files use
-.IR tzfile (5)
+.BR tzfile (5)
 format.
 .PP
 Input files should be text files, that is, they should be a series of