diff --git a/lib/libc/strchr.c b/lib/libc/strchr.c
index 61244da..d94bb9e 100644
--- a/lib/libc/strchr.c
+++ b/lib/libc/strchr.c
@@ -29,11 +29,10 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)index.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+/*
+ * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * All rights reserved.
+ */
 
 #include <stddef.h>
 #include <string.h>
@@ -52,5 +51,3 @@
 	}
 	/* NOTREACHED */
 }
-
-__weak_reference(strchr, index);
diff --git a/lib/libc/strcmp.c b/lib/libc/strcmp.c
index 63cb446..b742f9b 100644
--- a/lib/libc/strcmp.c
+++ b/lib/libc/strcmp.c
@@ -32,11 +32,10 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)strcmp.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+/*
+ * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * All rights reserved.
+ */
 
 #include <string.h>
 
diff --git a/lib/libc/strncmp.c b/lib/libc/strncmp.c
index c68fe00..ce9e5ed 100644
--- a/lib/libc/strncmp.c
+++ b/lib/libc/strncmp.c
@@ -29,11 +29,10 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)strncmp.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+/*
+ * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * All rights reserved.
+ */
 
 #include <string.h>
 
diff --git a/lib/libc/strnlen.c b/lib/libc/strnlen.c
index fca7ad2..b944e95 100644
--- a/lib/libc/strnlen.c
+++ b/lib/libc/strnlen.c
@@ -26,8 +26,10 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+/*
+ * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * All rights reserved.
+ */
 
 #include <string.h>