diff --git a/usr.sbin/iostat/iostat.8 b/usr.sbin/iostat/iostat.8
index 679dfc66b520..034bf71de0a1 100644
--- a/usr.sbin/iostat/iostat.8
+++ b/usr.sbin/iostat/iostat.8
@@ -118,6 +118,8 @@ seeks and rotational latency)
 % of cpu time in user mode running niced processes
 .It \&sy
 % of cpu time in system mode
+.It \&in
+% of cpu time in interrupt mode
 .It \&id
 % of cpu time in idle mode
 .El
diff --git a/usr.sbin/iostat/iostat.c b/usr.sbin/iostat/iostat.c
index f2925e875125..1d646e2ed08a 100644
--- a/usr.sbin/iostat/iostat.c
+++ b/usr.sbin/iostat/iostat.c
@@ -339,7 +339,7 @@ phdr(signo)
 	for (i = 0; i < dk_ndrive; i++)
 		if (dr_select[i])
 			(void)printf(" sps tps msps ");
-	(void)printf(" us ni sy id\n");
+	(void)printf(" us ni sy in id\n");
 }
 
 void