diff --git a/usr.bin/cmp/Makefile b/usr.bin/cmp/Makefile
index 6ec82e4f874..90a4c8e17c2 100644
--- a/usr.bin/cmp/Makefile
+++ b/usr.bin/cmp/Makefile
@@ -3,5 +3,6 @@
 
 PROG=	cmp
 SRCS=	cmp.c misc.c regular.c special.c
+WARNS?=	2
 
 .include <bsd.prog.mk>
diff --git a/usr.bin/cmp/cmp.c b/usr.bin/cmp/cmp.c
index 3d1e55f85b9..7a3d514a7fd 100644
--- a/usr.bin/cmp/cmp.c
+++ b/usr.bin/cmp/cmp.c
@@ -29,20 +29,21 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- * $FreeBSD$
- *
  */
 
+#include <sys/cdefs.h>
+
+__FBSDID("$FreeBSD$");
+
 #ifndef lint
 static const char copyright[] =
 "@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
 	The Regents of the University of California.  All rights reserved.\n";
-#endif /* not lint */
+#endif
 
 #ifndef lint
 static const char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
-#endif /* not lint */
+#endif
 
 #include <sys/types.h>
 #include <sys/stat.h>
diff --git a/usr.bin/cmp/misc.c b/usr.bin/cmp/misc.c
index 258d8606396..686fc191f2c 100644
--- a/usr.bin/cmp/misc.c
+++ b/usr.bin/cmp/misc.c
@@ -29,14 +29,15 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- * $FreeBSD$
- *
  */
 
+#include <sys/cdefs.h>
+
+__FBSDID("$FreeBSD$");
+
 #ifndef lint
 static const char sccsid[] = "@(#)misc.c	8.3 (Berkeley) 4/2/94";
-#endif /* not lint */
+#endif
 
 #include <sys/types.h>
 
diff --git a/usr.bin/cmp/regular.c b/usr.bin/cmp/regular.c
index 3c0b5ae1712..bf15a73fecb 100644
--- a/usr.bin/cmp/regular.c
+++ b/usr.bin/cmp/regular.c
@@ -29,14 +29,15 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- * $FreeBSD$
- *
  */
 
+#include <sys/cdefs.h>
+
+__FBSDID("$FreeBSD$");
+
 #ifndef lint
 static const char sccsid[] = "@(#)regular.c	8.3 (Berkeley) 4/2/94";
-#endif /* not lint */
+#endif
 
 #include <sys/param.h>
 #include <sys/mman.h>
diff --git a/usr.bin/cmp/special.c b/usr.bin/cmp/special.c
index 77d21bdd14e..be37f492647 100644
--- a/usr.bin/cmp/special.c
+++ b/usr.bin/cmp/special.c
@@ -29,14 +29,15 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- * $FreeBSD$
- *
  */
 
+#include <sys/cdefs.h>
+
+__FBSDID("$FreeBSD$");
+
 #ifndef lint
 static const char sccsid[] = "@(#)special.c	8.3 (Berkeley) 4/2/94";
-#endif /* not lint */
+#endif
 
 #include <sys/types.h>