diff --git a/drivers/arm/sbsa/sbsa.c b/drivers/arm/sbsa/sbsa.c
index 6f00a60..79c6f26 100644
--- a/drivers/arm/sbsa/sbsa.c
+++ b/drivers/arm/sbsa/sbsa.c
@@ -4,11 +4,11 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#include <plat/common/platform.h>
+#include <assert.h>
+#include <stdint.h>
 #include <drivers/arm/sbsa.h>
 #include <lib/mmio.h>
-#include <stdint_.h>
-#include <assert.h>
+#include <plat/common/platform.h>
 
 void sbsa_watchdog_offset_reg_write(uintptr_t base, uint64_t value)
 {
diff --git a/include/lib/libc/aarch32/stddef_.h b/include/lib/libc/aarch32/stddef_.h
index 1babfad..36dc20b 100644
--- a/include/lib/libc/aarch32/stddef_.h
+++ b/include/lib/libc/aarch32/stddef_.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -12,9 +12,4 @@
 #define SIZET_
 #endif
 
-#ifndef _PTRDIFF_T
-typedef long ptrdiff_t;
-#define _PTRDIFF_T
-#endif
-
 #endif /* STDDEF__H */
diff --git a/include/lib/libc/aarch32/stdint_.h b/include/lib/libc/aarch32/stdint_.h
deleted file mode 100644
index 4f49485..0000000
--- a/include/lib/libc/aarch32/stdint_.h
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#define INT8_MAX  0x7F
-#define INT8_MIN  (-INT8_MAX - 1)
-#define UINT8_MAX 0xFFU
-
-#define INT16_MAX  0x7FFF
-#define INT16_MIN  (-INT16_MAX - 1)
-#define UINT16_MAX 0xFFFFU
-
-#define INT32_MAX  0x7FFFFFFF
-#define INT32_MIN  (-INT32_MAX - 1)
-#define UINT32_MAX 0xFFFFFFFFU
-
-#define INT64_MAX  0x7FFFFFFFFFFFFFFFLL
-#define INT64_MIN  (-INT64_MAX - 1LL)
-#define UINT64_MAX 0xFFFFFFFFFFFFFFFFULL
-
-#define INT_LEAST8_MIN  INT8_MIN
-#define INT_LEAST8_MAX  INT8_MAX
-#define UINT_LEAST8_MAX UINT8_MAX
-
-#define INT_LEAST16_MIN  INT16_MIN
-#define INT_LEAST16_MAX  INT16_MAX
-#define UINT_LEAST16_MAX UINT16_MAX
-
-#define INT_LEAST32_MIN  INT32_MIN
-#define INT_LEAST32_MAX  INT32_MAX
-#define UINT_LEAST32_MAX UINT32_MAX
-
-#define INT_LEAST64_MIN  INT64_MIN
-#define INT_LEAST64_MAX  INT64_MAX
-#define UINT_LEAST64_MAX UINT64_MAX
-
-#define INT_FAST8_MIN  INT32_MIN
-#define INT_FAST8_MAX  INT32_MAX
-#define UINT_FAST8_MAX UINT32_MAX
-
-#define INT_FAST16_MIN  INT32_MIN
-#define INT_FAST16_MAX  INT32_MAX
-#define UINT_FAST16_MAX UINT32_MAX
-
-#define INT_FAST32_MIN  INT32_MIN
-#define INT_FAST32_MAX  INT32_MAX
-#define UINT_FAST32_MAX UINT32_MAX
-
-#define INT_FAST64_MIN  INT64_MIN
-#define INT_FAST64_MAX  INT64_MAX
-#define UINT_FAST64_MAX UINT64_MAX
-
-#define INTPTR_MIN  INT32_MIN
-#define INTPTR_MAX  INT32_MAX
-#define UINTPTR_MAX UINT32_MAX
-
-#define INTMAX_MIN  INT64_MIN
-#define INTMAX_MAX  INT64_MAX
-#define UINTMAX_MAX UINT64_MAX
-
-#define PTRDIFF_MIN INT32_MIN
-#define PTRDIFF_MAX INT32_MAX
-
-#define SIZE_MAX UINT32_MAX
-
-#define INT8_C(x)  x
-#define INT16_C(x) x
-#define INT32_C(x) x
-#define INT64_C(x) x ## LL
-
-#define UINT8_C(x)  x
-#define UINT16_C(x) x
-#define UINT32_C(x) x ## U
-#define UINT64_C(x) x ## ULL
-
-#define INTMAX_C(x)  x ## LL
-#define UINTMAX_C(x) x ## ULL
-
-typedef signed char int8_t;
-typedef short int16_t;
-typedef int int32_t;
-typedef long long int64_t;
-
-typedef unsigned char uint8_t;
-typedef unsigned short uint16_t;
-typedef unsigned int uint32_t;
-typedef unsigned long long uint64_t;
-
-typedef signed char int8_least_t;
-typedef short int16_least_t;
-typedef int int32_least_t;
-typedef long long int64_least_t;
-
-typedef unsigned char uint8_least_t;
-typedef unsigned short uint16_least_t;
-typedef unsigned int uint32_least_t;
-typedef unsigned long long uint64_least_t;
-
-typedef int int8_fast_t;
-typedef int int16_fast_t;
-typedef int int32_fast_t;
-typedef long long int64_fast_t;
-
-typedef unsigned int uint8_fast_t;
-typedef unsigned int uint16_fast_t;
-typedef unsigned int uint32_fast_t;
-typedef unsigned long long uint64_fast_t;
-
-typedef long intptr_t;
-typedef unsigned long uintptr_t;
-
-typedef long long intmax_t;
-typedef unsigned long long uintmax_t;
-
-typedef long register_t;
-typedef unsigned long u_register_t;
diff --git a/include/lib/libc/aarch32/stdio_.h b/include/lib/libc/aarch32/stdio_.h
index 50d3cc2..5e49425 100644
--- a/include/lib/libc/aarch32/stdio_.h
+++ b/include/lib/libc/aarch32/stdio_.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,11 +7,6 @@
 #ifndef STDIO__H
 #define STDIO__H
 
-#ifndef SIZET_
-typedef unsigned int size_t;
-#define SIZET_
-#endif
-
 #ifndef SSIZET_
 typedef int ssize_t;
 #define SSIZET_
diff --git a/include/lib/libc/aarch32/stdlib_.h b/include/lib/libc/aarch32/stdlib_.h
deleted file mode 100644
index 9c07857..0000000
--- a/include/lib/libc/aarch32/stdlib_.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef STDLIB__H
-#define STDLIB__H
-
-#ifndef SIZET_
-typedef unsigned int size_t;
-#define SIZET_
-#endif
-
-#define EXIT_FAILURE 1
-#define EXIT_SUCCESS 0
-
-#endif /* STDLIB__H */
diff --git a/include/lib/libc/aarch32/string_.h b/include/lib/libc/aarch32/string_.h
deleted file mode 100644
index 4e139b0..0000000
--- a/include/lib/libc/aarch32/string_.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef STRING__H
-#define STRING__H
-
-#ifndef SIZET_
-typedef unsigned int size_t;
-#define SIZET_
-#endif
-
-#endif /* STRING__H */
diff --git a/include/lib/libc/aarch32/time_.h b/include/lib/libc/aarch32/time_.h
deleted file mode 100644
index a9169c2..0000000
--- a/include/lib/libc/aarch32/time_.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef TIME__H
-#define TIME__H
-
-#ifndef SIZET_
-typedef unsigned int size_t;
-#define SIZET_
-#endif
-
-typedef long int time_t;
-
-#endif /* TIME__H */
diff --git a/include/lib/libc/aarch64/stddef_.h b/include/lib/libc/aarch64/stddef_.h
index b7d8209..6ecc606 100644
--- a/include/lib/libc/aarch64/stddef_.h
+++ b/include/lib/libc/aarch64/stddef_.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -12,9 +12,4 @@
 #define SIZET_
 #endif
 
-#ifndef _PTRDIFF_T
-typedef long ptrdiff_t;
-#define _PTRDIFF_T
-#endif
-
 #endif /* STDDEF__H */
diff --git a/include/lib/libc/aarch64/stdint_.h b/include/lib/libc/aarch64/stdint_.h
deleted file mode 100644
index b17a435..0000000
--- a/include/lib/libc/aarch64/stdint_.h
+++ /dev/null
@@ -1,121 +0,0 @@
-/*
- * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#define INT8_MAX  0x7F
-#define INT8_MIN  (-INT8_MAX - 1)
-#define UINT8_MAX 0xFFU
-
-#define INT16_MAX  0x7FFF
-#define INT16_MIN  (-INT16_MAX - 1)
-#define UINT16_MAX 0xFFFFU
-
-#define INT32_MAX  0x7FFFFFFF
-#define INT32_MIN  (-INT32_MAX - 1)
-#define UINT32_MAX 0xFFFFFFFFU
-
-#define INT64_MAX  0x7FFFFFFFFFFFFFFFLL
-#define INT64_MIN  (-INT64_MAX - 1LL)
-#define UINT64_MAX 0xFFFFFFFFFFFFFFFFULL
-
-#define INT_LEAST8_MIN  INT8_MIN
-#define INT_LEAST8_MAX  INT8_MAX
-#define UINT_LEAST8_MAX UINT8_MAX
-
-#define INT_LEAST16_MIN  INT16_MIN
-#define INT_LEAST16_MAX  INT16_MAX
-#define UINT_LEAST16_MAX UINT16_MAX
-
-#define INT_LEAST32_MIN  INT32_MIN
-#define INT_LEAST32_MAX  INT32_MAX
-#define UINT_LEAST32_MAX UINT32_MAX
-
-#define INT_LEAST64_MIN  INT64_MIN
-#define INT_LEAST64_MAX  INT64_MAX
-#define UINT_LEAST64_MAX UINT64_MAX
-
-#define INT_FAST8_MIN  INT32_MIN
-#define INT_FAST8_MAX  INT32_MAX
-#define UINT_FAST8_MAX UINT32_MAX
-
-#define INT_FAST16_MIN  INT32_MIN
-#define INT_FAST16_MAX  INT32_MAX
-#define UINT_FAST16_MAX UINT32_MAX
-
-#define INT_FAST32_MIN  INT32_MIN
-#define INT_FAST32_MAX  INT32_MAX
-#define UINT_FAST32_MAX UINT32_MAX
-
-#define INT_FAST64_MIN  INT64_MIN
-#define INT_FAST64_MAX  INT64_MAX
-#define UINT_FAST64_MAX UINT64_MAX
-
-#define INTPTR_MIN  INT64_MIN
-#define INTPTR_MAX  INT64_MAX
-#define UINTPTR_MAX UINT64_MAX
-
-#define INTMAX_MIN  INT64_MIN
-#define INTMAX_MAX  INT64_MAX
-#define UINTMAX_MAX UINT64_MAX
-
-#define PTRDIFF_MIN INT64_MIN
-#define PTRDIFF_MAX INT64_MAX
-
-#define SIZE_MAX UINT64_MAX
-
-#define INT8_C(x)  x
-#define INT16_C(x) x
-#define INT32_C(x) x
-#define INT64_C(x) x ## LL
-
-#define UINT8_C(x)  x
-#define UINT16_C(x) x
-#define UINT32_C(x) x ## U
-#define UINT64_C(x) x ## ULL
-
-#define INTMAX_C(x)  x ## L
-#define UINTMAX_C(x) x ## ULL
-
-typedef signed char int8_t;
-typedef short int16_t;
-typedef int int32_t;
-typedef long long int64_t;
-
-typedef unsigned char uint8_t;
-typedef unsigned short uint16_t;
-typedef unsigned int uint32_t;
-typedef unsigned long long uint64_t;
-
-typedef signed char int8_least_t;
-typedef short int16_least_t;
-typedef int int32_least_t;
-typedef long long int64_least_t;
-
-typedef unsigned char uint8_least_t;
-typedef unsigned short uint16_least_t;
-typedef unsigned int uint32_least_t;
-typedef unsigned long long uint64_least_t;
-
-typedef int int8_fast_t;
-typedef int int16_fast_t;
-typedef int int32_fast_t;
-typedef long long int64_fast_t;
-
-typedef unsigned int uint8_fast_t;
-typedef unsigned int uint16_fast_t;
-typedef unsigned int uint32_fast_t;
-typedef unsigned long long uint64_fast_t;
-
-typedef long intptr_t;
-typedef unsigned long uintptr_t;
-
-typedef long intmax_t;
-typedef unsigned long uintmax_t;
-
-typedef long register_t;
-typedef unsigned long u_register_t;
-
-typedef __int128 int128_t;
-typedef unsigned __int128 uint128_t;
diff --git a/include/lib/libc/aarch64/stdio_.h b/include/lib/libc/aarch64/stdio_.h
index 09b0172..afaeadc 100644
--- a/include/lib/libc/aarch64/stdio_.h
+++ b/include/lib/libc/aarch64/stdio_.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,11 +7,6 @@
 #ifndef STDIO__H
 #define STDIO__H
 
-#ifndef SIZET_
-typedef unsigned long size_t;
-#define SIZET_
-#endif
-
 #ifndef SSIZET_
 typedef long ssize_t;
 #define SSIZET_
diff --git a/include/lib/libc/aarch64/stdlib_.h b/include/lib/libc/aarch64/stdlib_.h
deleted file mode 100644
index 81a39d1..0000000
--- a/include/lib/libc/aarch64/stdlib_.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef STDLIB__H
-#define STDLIB__H
-
-#ifndef SIZET_
-typedef unsigned long size_t;
-#define SIZET_
-#endif
-
-#define EXIT_FAILURE 1
-#define EXIT_SUCCESS 0
-
-#endif /* STDLIB__H */
diff --git a/include/lib/libc/aarch64/string_.h b/include/lib/libc/aarch64/string_.h
deleted file mode 100644
index 71c51a6..0000000
--- a/include/lib/libc/aarch64/string_.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef STRING__H
-#define STRING__H
-
-#ifndef SIZET_
-typedef unsigned long size_t;
-#define SIZET_
-#endif
-
-#endif /* STRING__H */
diff --git a/include/lib/libc/aarch64/time_.h b/include/lib/libc/aarch64/time_.h
deleted file mode 100644
index 68ab1b8..0000000
--- a/include/lib/libc/aarch64/time_.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef TIME__H
-#define TIME__H
-
-#ifndef SIZET_
-typedef unsigned long size_t;
-#define SIZET_
-#endif
-
-typedef long int time_t;
-
-#endif /* TIME__H */
diff --git a/include/lib/libc/stddef.h b/include/lib/libc/stddef.h
index c9957bd..58a519e 100644
--- a/include/lib/libc/stddef.h
+++ b/include/lib/libc/stddef.h
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 /*
- * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * Portions copyright (c) 2018-2019, ARM Limited and Contributors.
  * All rights reserved.
  */
 
@@ -13,6 +13,11 @@
 
 #include <stddef_.h>
 
+#ifndef _PTRDIFF_T
+typedef long ptrdiff_t;
+#define _PTRDIFF_T
+#endif
+
 #ifndef NULL
 #define NULL ((void *) 0)
 #endif
diff --git a/include/lib/libc/stdint.h b/include/lib/libc/stdint.h
index d44a973..80b3e96 100644
--- a/include/lib/libc/stdint.h
+++ b/include/lib/libc/stdint.h
@@ -4,13 +4,135 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 /*
- * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * Portions copyright (c) 2018-2019, ARM Limited and Contributors.
  * All rights reserved.
  */
 
 #ifndef STDINT_H
 #define STDINT_H
 
-#include <stdint_.h>
+#include <limits.h>
+
+#define INT8_MAX  CHAR_MAX
+#define INT8_MIN  CHAR_MIN
+#define UINT8_MAX UCHAR_MAX
+
+#define INT16_MAX  SHRT_MAX
+#define INT16_MIN  SHRT_MIN
+#define UINT16_MAX USHRT_MAX
+
+#define INT32_MAX  INT_MAX
+#define INT32_MIN  INT_MIN
+#define UINT32_MAX UINT_MAX
+
+#define INT64_MAX  LLONG_MAX
+#define INT64_MIN  LLONG_MIN
+#define UINT64_MAX ULLONG_MAX
+
+#define INT_LEAST8_MIN  INT8_MIN
+#define INT_LEAST8_MAX  INT8_MAX
+#define UINT_LEAST8_MAX UINT8_MAX
+
+#define INT_LEAST16_MIN  INT16_MIN
+#define INT_LEAST16_MAX  INT16_MAX
+#define UINT_LEAST16_MAX UINT16_MAX
+
+#define INT_LEAST32_MIN  INT32_MIN
+#define INT_LEAST32_MAX  INT32_MAX
+#define UINT_LEAST32_MAX UINT32_MAX
+
+#define INT_LEAST64_MIN  INT64_MIN
+#define INT_LEAST64_MAX  INT64_MAX
+#define UINT_LEAST64_MAX UINT64_MAX
+
+#define INT_FAST8_MIN  INT32_MIN
+#define INT_FAST8_MAX  INT32_MAX
+#define UINT_FAST8_MAX UINT32_MAX
+
+#define INT_FAST16_MIN  INT32_MIN
+#define INT_FAST16_MAX  INT32_MAX
+#define UINT_FAST16_MAX UINT32_MAX
+
+#define INT_FAST32_MIN  INT32_MIN
+#define INT_FAST32_MAX  INT32_MAX
+#define UINT_FAST32_MAX UINT32_MAX
+
+#define INT_FAST64_MIN  INT64_MIN
+#define INT_FAST64_MAX  INT64_MAX
+#define UINT_FAST64_MAX UINT64_MAX
+
+#define INTPTR_MIN  LONG_MIN
+#define INTPTR_MAX  LONG_MAX
+#define UINTPTR_MAX ULONG_MAX
+
+#define INTMAX_MIN  LLONG_MIN
+#define INTMAX_MAX  LLONG_MAX
+#define UINTMAX_MAX ULLONG_MAX
+
+#define PTRDIFF_MIN LONG_MIN
+#define PTRDIFF_MAX LONG_MAX
+
+#define SIZE_MAX UINT64_MAX
+
+#define INT8_C(x)  x
+#define INT16_C(x) x
+#define INT32_C(x) x
+#define INT64_C(x) x ## LL
+
+#define UINT8_C(x)  x
+#define UINT16_C(x) x
+#define UINT32_C(x) x ## U
+#define UINT64_C(x) x ## ULL
+
+#define INTMAX_C(x)  x ## LL
+#define UINTMAX_C(x) x ## ULL
+
+typedef signed char int8_t;
+typedef short int16_t;
+typedef int int32_t;
+typedef long long int64_t;
+
+typedef unsigned char uint8_t;
+typedef unsigned short uint16_t;
+typedef unsigned int uint32_t;
+typedef unsigned long long uint64_t;
+
+typedef signed char int8_least_t;
+typedef short int16_least_t;
+typedef int int32_least_t;
+typedef long long int64_least_t;
+
+typedef unsigned char uint8_least_t;
+typedef unsigned short uint16_least_t;
+typedef unsigned int uint32_least_t;
+typedef unsigned long long uint64_least_t;
+
+typedef int int8_fast_t;
+typedef int int16_fast_t;
+typedef int int32_fast_t;
+typedef long long int64_fast_t;
+
+typedef unsigned int uint8_fast_t;
+typedef unsigned int uint16_fast_t;
+typedef unsigned int uint32_fast_t;
+typedef unsigned long long uint64_fast_t;
+
+typedef long intptr_t;
+typedef unsigned long uintptr_t;
+
+/*
+* Conceptually, these are supposed to be the largest integers representable in C,
+* but GCC and Clang define them as long long for compatibility.
+*/
+typedef long long intmax_t;
+typedef unsigned long long uintmax_t;
+
+typedef long register_t;
+typedef unsigned long u_register_t;
+
+#ifdef __aarch64__
+typedef __int128 int128_t;
+typedef unsigned __int128 uint128_t;
+#endif /* __aarch64__ */
 
 #endif /* STDINT_H */
diff --git a/include/lib/libc/stdio.h b/include/lib/libc/stdio.h
index 3d9323e..2d9e655 100644
--- a/include/lib/libc/stdio.h
+++ b/include/lib/libc/stdio.h
@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 /*
- * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * Portions copyright (c) 2018-2019, ARM Limited and Contributors.
  * All rights reserved.
  */
 
@@ -12,12 +12,9 @@
 #define STDIO_H
 
 #include <cdefs.h>
+#include <stddef.h>
 #include <stdio_.h>
 
-#ifndef NULL
-#define NULL ((void *) 0)
-#endif
-
 #define EOF            -1
 
 int printf(const char *fmt, ...) __printflike(1, 2);
diff --git a/include/lib/libc/stdlib.h b/include/lib/libc/stdlib.h
index edd6265..24e7bae 100644
--- a/include/lib/libc/stdlib.h
+++ b/include/lib/libc/stdlib.h
@@ -4,18 +4,17 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 /*
- * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * Portions copyright (c) 2018-2019, ARM Limited and Contributors.
  * All rights reserved.
  */
 
 #ifndef STDLIB_H
 #define STDLIB_H
 
-#include <stdlib_.h>
+#include <stddef.h>
 
-#ifndef NULL
-#define NULL ((void *) 0)
-#endif
+#define EXIT_FAILURE 1
+#define EXIT_SUCCESS 0
 
 #define _ATEXIT_MAX 1
 
diff --git a/include/lib/libc/string.h b/include/lib/libc/string.h
index ee6eeac..c92b680 100644
--- a/include/lib/libc/string.h
+++ b/include/lib/libc/string.h
@@ -4,18 +4,14 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 /*
- * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * Portions copyright (c) 2018-2019, ARM Limited and Contributors.
  * All rights reserved.
  */
 
 #ifndef STRING_H
 #define STRING_H
 
-#include <string_.h>
-
-#ifndef NULL
-#define NULL ((void *) 0)
-#endif
+#include <stddef.h>
 
 void *memcpy(void *dst, const void *src, size_t len);
 void *memmove(void *dst, const void *src, size_t len);
diff --git a/include/lib/libc/time.h b/include/lib/libc/time.h
index 71d3e7e..c1c95e5 100644
--- a/include/lib/libc/time.h
+++ b/include/lib/libc/time.h
@@ -4,17 +4,15 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 /*
- * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * Portions copyright (c) 2018-2019, ARM Limited and Contributors.
  * All rights reserved.
  */
 
 #ifndef TIME_H
 #define TIME_H
 
-#include <time_.h>
+#include <stddef.h>
 
-#ifndef NULL
-#define NULL ((void *) 0)
-#endif
+typedef long int time_t;
 
 #endif /* TIME_H */