diff --git a/man2/setup.2 b/man2/setup.2
index a97b5f605..2e047c707 100644
--- a/man2/setup.2
+++ b/man2/setup.2
@@ -64,7 +64,7 @@ This function is Linux-specific, and should not be used in programs
 intended to be portable, or indeed in any programs at all.
 .SH NOTES
 The calling sequence varied: at some times
-.I setup ()
+.BR setup ()
 has had a single argument
 .I "void\ *BIOS"
 and at other times a single argument