diff --git a/usr.bin/tail/forward.c b/usr.bin/tail/forward.c
index 51eaeca9be5..1d5f710a06c 100644
--- a/usr.bin/tail/forward.c
+++ b/usr.bin/tail/forward.c
@@ -50,6 +50,7 @@ static char sccsid[] = "@(#)forward.c	8.1 (Berkeley) 6/6/93";
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <err.h>
 #include "extern.h"
 
 static void rlines __P((FILE *, long, struct stat *));
diff --git a/usr.bin/tail/misc.c b/usr.bin/tail/misc.c
index fb38d76fe90..a396fc30eea 100644
--- a/usr.bin/tail/misc.c
+++ b/usr.bin/tail/misc.c
@@ -45,6 +45,7 @@ static char sccsid[] = "@(#)misc.c	8.1 (Berkeley) 6/6/93";
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <err.h>
 #include "extern.h"
 
 void
diff --git a/usr.bin/tail/read.c b/usr.bin/tail/read.c
index 1871c513f6d..feecf3cc53d 100644
--- a/usr.bin/tail/read.c
+++ b/usr.bin/tail/read.c
@@ -46,6 +46,7 @@ static char sccsid[] = "@(#)read.c	8.1 (Berkeley) 6/6/93";
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <err.h>
 #include "extern.h"
 
 /*
diff --git a/usr.bin/tail/reverse.c b/usr.bin/tail/reverse.c
index 248cb69c819..3573ec63b79 100644
--- a/usr.bin/tail/reverse.c
+++ b/usr.bin/tail/reverse.c
@@ -48,6 +48,7 @@ static char sccsid[] = "@(#)reverse.c	8.1 (Berkeley) 6/6/93";
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <err.h>
 #include "extern.h"
 
 static void r_buf __P((FILE *));
diff --git a/usr.bin/tail/tail.c b/usr.bin/tail/tail.c
index e8005908159..9e2223f6456 100644
--- a/usr.bin/tail/tail.c
+++ b/usr.bin/tail/tail.c
@@ -51,6 +51,7 @@ static char sccsid[] = "@(#)tail.c	8.1 (Berkeley) 6/6/93";
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <err.h>
 #include "extern.h"
 
 int fflag, rflag, rval;