diff --git a/usr.bin/gprof/gprof.c b/usr.bin/gprof/gprof.c
index 7b857b8bb9d6..6f139ab27202 100644
--- a/usr.bin/gprof/gprof.c
+++ b/usr.bin/gprof/gprof.c
@@ -49,6 +49,8 @@ __FBSDID("$FreeBSD$");
 #include <err.h>
 #include <limits.h>
 #include <stdint.h>
+#include <string.h>
+
 #include "gprof.h"
 
 static int valcmp(const void *, const void *);
diff --git a/usr.bin/gprof/kernel.c b/usr.bin/gprof/kernel.c
index fc140877909c..38cc91e369d2 100644
--- a/usr.bin/gprof/kernel.c
+++ b/usr.bin/gprof/kernel.c
@@ -8,6 +8,7 @@ __FBSDID("$FreeBSD$");
 
 #include <err.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "gprof.h"
 
diff --git a/usr.bin/gprof/printgprof.c b/usr.bin/gprof/printgprof.c
index de1fe49d52e2..4ca539588c73 100644
--- a/usr.bin/gprof/printgprof.c
+++ b/usr.bin/gprof/printgprof.c
@@ -41,6 +41,8 @@ static char sccsid[] = "@(#)printgprof.c	8.1 (Berkeley) 6/6/93";
 __FBSDID("$FreeBSD$");
 
 #include <err.h>
+#include <string.h>
+
 #include "gprof.h"
 #include "pathnames.h"
 
diff --git a/usr.bin/gprof/printlist.c b/usr.bin/gprof/printlist.c
index c5ecdf7d1633..ed68bcc0d313 100644
--- a/usr.bin/gprof/printlist.c
+++ b/usr.bin/gprof/printlist.c
@@ -41,6 +41,8 @@ static char sccsid[] = "@(#)printlist.c	8.1 (Berkeley) 6/6/93";
 __FBSDID("$FreeBSD$");
 
 #include <err.h>
+#include <string.h>
+
 #include "gprof.h"
 
     /*
diff --git a/usr.sbin/mrouted/testrsrr/testrsrr.c b/usr.sbin/mrouted/testrsrr/testrsrr.c
index b18d6b028882..6dfe831b47ef 100644
--- a/usr.sbin/mrouted/testrsrr/testrsrr.c
+++ b/usr.sbin/mrouted/testrsrr/testrsrr.c
@@ -31,6 +31,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <err.h>
 #include <sysexits.h>