diff --git a/lib/libc/memchr.c b/lib/libc/memchr.c
index 2eba47c..0fe0535 100644
--- a/lib/libc/memchr.c
+++ b/lib/libc/memchr.c
@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <stddef.h>
+#include <string.h>
 
 void *memchr(const void *src, int c, size_t len)
 {
diff --git a/lib/libc/memcmp.c b/lib/libc/memcmp.c
index a4c798b..cd5f0df 100644
--- a/lib/libc/memcmp.c
+++ b/lib/libc/memcmp.c
@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <stddef.h>
+#include <string.h>
 
 int memcmp(const void *s1, const void *s2, size_t len)
 {
diff --git a/lib/libc/memcpy.c b/lib/libc/memcpy.c
index fc0c9fe..158df9b 100644
--- a/lib/libc/memcpy.c
+++ b/lib/libc/memcpy.c
@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <stddef.h>
+#include <string.h>
 
 void *memcpy(void *dst, const void *src, size_t len)
 {
diff --git a/lib/libc/memset.c b/lib/libc/memset.c
index 03aa809..d8007d8 100644
--- a/lib/libc/memset.c
+++ b/lib/libc/memset.c
@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <stddef.h>
+#include <string.h>
 
 void *memset(void *dst, int val, size_t count)
 {