diff --git a/CMakeLists.txt b/CMakeLists.txt
index 700c3a958..d419d8202 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -220,7 +220,6 @@ set(SOURCES_H
   crypto/include/datatypes.h
   crypto/include/err.h
   crypto/include/hmac.h
-  crypto/include/integers.h
   crypto/include/key.h
   crypto/include/null_auth.h
   crypto/include/null_cipher.h
diff --git a/crypto/cipher/cipher.c b/crypto/cipher/cipher.c
index 35a2321b6..4458c276b 100644
--- a/crypto/cipher/cipher.c
+++ b/crypto/cipher/cipher.c
@@ -54,6 +54,8 @@
 #include "err.h"   /* for srtp_debug */
 #include "alloc.h" /* for crypto_alloc(), crypto_free()  */
 
+#include <stdlib.h>
+
 srtp_debug_module_t srtp_mod_cipher = {
     false,   /* debugging is off by default */
     "cipher" /* printable module name       */
diff --git a/crypto/include/datatypes.h b/crypto/include/datatypes.h
index 4510cc870..a64fd0cd9 100644
--- a/crypto/include/datatypes.h
+++ b/crypto/include/datatypes.h
@@ -46,13 +46,8 @@
 #ifndef DATATYPES_H
 #define DATATYPES_H
 
-#include "integers.h" /* definitions of uint32_t, et cetera   */
-#include "alloc.h"
-
-#include <stdarg.h>
+#include <inttypes.h>
 #include <stdbool.h>
-
-#include <stdio.h>
 #include <string.h>
 #include <time.h>
 #ifdef HAVE_NETINET_IN_H
diff --git a/crypto/include/integers.h b/crypto/include/integers.h
deleted file mode 100644
index 01136d631..000000000
--- a/crypto/include/integers.h
+++ /dev/null
@@ -1,103 +0,0 @@
-/*
- * integers.h
- *
- * defines integer types (or refers to their definitions)
- *
- * David A. McGrew
- * Cisco Systems, Inc.
- */
-
-/*
- *
- * Copyright (c) 2001-2017, Cisco Systems, Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- *   Redistributions of source code must retain the above copyright
- *   notice, this list of conditions and the following disclaimer.
- *
- *   Redistributions in binary form must reproduce the above
- *   copyright notice, this list of conditions and the following
- *   disclaimer in the documentation and/or other materials provided
- *   with the distribution.
- *
- *   Neither the name of the Cisco Systems, Inc. nor the names of its
- *   contributors may be used to endorse or promote products derived
- *   from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT 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.
- *
- */
-
-#ifndef INTEGERS_H
-#define INTEGERS_H
-
-/* use standard integer definitions, if they're available  */
-#ifdef HAVE_STDLIB_H
-#include <stdlib.h>
-#endif
-#ifdef HAVE_STDINT_H
-#include <stdint.h>
-#endif
-#ifdef HAVE_INTTYPES_H
-#include <inttypes.h>
-#endif
-#ifdef HAVE_SYS_TYPES_H
-#include <sys/types.h>
-#endif
-#ifdef HAVE_SYS_INT_TYPES_H
-#include <sys/int_types.h> /* this exists on Sun OS */
-#endif
-#ifdef HAVE_MACHINE_TYPES_H
-#include <machine/types.h>
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* Can we do 64 bit integers? */
-#if !defined(HAVE_UINT64_T)
-#if SIZEOF_UNSIGNED_LONG == 8
-typedef unsigned long uint64_t;
-#elif SIZEOF_UNSIGNED_LONG_LONG == 8
-typedef unsigned long long uint64_t;
-#else
-#error "NO_64BIT_MATH"
-#endif
-#endif
-
-/* Reasonable defaults for 32 bit machines - you may need to
- * edit these definitions for your own machine. */
-#ifndef HAVE_UINT8_T
-typedef unsigned char uint8_t;
-#endif
-#ifndef HAVE_UINT16_T
-typedef unsigned short int uint16_t;
-#endif
-#ifndef HAVE_UINT32_T
-typedef unsigned int uint32_t;
-#endif
-#ifndef HAVE_INT32_T
-typedef int int32_t;
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* INTEGERS_H */
diff --git a/crypto/include/rdb.h b/crypto/include/rdb.h
index 208dff3ff..f65925e4a 100644
--- a/crypto/include/rdb.h
+++ b/crypto/include/rdb.h
@@ -46,7 +46,6 @@
 #ifndef REPLAY_DB_H
 #define REPLAY_DB_H
 
-#include "integers.h"  /* for uint32_t     */
 #include "datatypes.h" /* for v128_t       */
 #include "err.h"       /* for srtp_err_status_t */
 
diff --git a/crypto/kernel/alloc.c b/crypto/kernel/alloc.c
index f36152d58..d48aae55e 100644
--- a/crypto/kernel/alloc.c
+++ b/crypto/kernel/alloc.c
@@ -49,6 +49,8 @@
 #include "alloc.h"
 #include "crypto_kernel.h"
 
+#include <stdlib.h>
+
 /* the debug module for memory allocation */
 
 srtp_debug_module_t srtp_mod_alloc = {
@@ -65,8 +67,6 @@ srtp_debug_module_t srtp_mod_alloc = {
  * address.
  */
 
-#if defined(HAVE_STDLIB_H)
-
 void *srtp_crypto_alloc(size_t size)
 {
     void *ptr;
@@ -93,9 +93,3 @@ void srtp_crypto_free(void *ptr)
 
     free(ptr);
 }
-
-#else /* we need to define our own memory allocation routines */
-
-#error no memory allocation defined yet
-
-#endif
diff --git a/crypto/kernel/crypto_kernel.c b/crypto/kernel/crypto_kernel.c
index b83d3a164..f85a5ffbb 100644
--- a/crypto/kernel/crypto_kernel.c
+++ b/crypto/kernel/crypto_kernel.c
@@ -46,10 +46,11 @@
 #include <config.h>
 #endif
 
-#include "alloc.h"
-
 #include "crypto_kernel.h"
 #include "cipher_types.h"
+#include "alloc.h"
+
+#include <stdlib.h>
 
 /* the debug module for the crypto_kernel */
 
diff --git a/crypto/math/datatypes.c b/crypto/math/datatypes.c
index 9930fcd7c..5daaf1258 100644
--- a/crypto/math/datatypes.c
+++ b/crypto/math/datatypes.c
@@ -47,12 +47,13 @@
 #include <config.h>
 #endif
 
+#include "datatypes.h"
+#include "alloc.h"
+
 #ifdef OPENSSL
 #include <openssl/crypto.h>
 #endif
 
-#include "datatypes.h"
-
 #if defined(__SSE2__)
 #include <tmmintrin.h>
 #endif
diff --git a/crypto/test/aes_calc.c b/crypto/test/aes_calc.c
index 0a2a22751..9aaa54f33 100644
--- a/crypto/test/aes_calc.c
+++ b/crypto/test/aes_calc.c
@@ -61,9 +61,11 @@
 #endif
 
 #include "aes.h"
+#include "util.h"
+
 #include <stdio.h>
 #include <string.h>
-#include "util.h"
+#include <stdlib.h>
 
 void usage(char *prog_name)
 {
diff --git a/crypto/test/cipher_driver.c b/crypto/test/cipher_driver.c
index 89806b024..f15073efb 100644
--- a/crypto/test/cipher_driver.c
+++ b/crypto/test/cipher_driver.c
@@ -47,11 +47,14 @@
 #include <config.h>
 #endif
 
-#include <stdio.h> /* for printf() */
 #include "getopt_s.h"
 #include "cipher.h"
 #include "cipher_priv.h"
 #include "datatypes.h"
+#include "alloc.h"
+
+#include <stdio.h> /* for printf() */
+#include <stdlib.h>
 
 #define PRINT_DEBUG 0
 
diff --git a/crypto/test/datatypes_driver.c b/crypto/test/datatypes_driver.c
index b30401935..f4b613606 100644
--- a/crypto/test/datatypes_driver.c
+++ b/crypto/test/datatypes_driver.c
@@ -47,11 +47,13 @@
 #include <config.h>
 #endif
 
-#include <stdio.h>  /* for printf() */
-#include <string.h> /* for strlen() */
 #include "datatypes.h"
 #include "util.h"
 
+#include <stdio.h>  /* for printf() */
+#include <string.h> /* for strlen() */
+#include <stdlib.h>
+
 void byte_order(void);
 
 void test_hex_string_funcs(void);
diff --git a/crypto/test/kernel_driver.c b/crypto/test/kernel_driver.c
index ada85dca3..e305b6d30 100644
--- a/crypto/test/kernel_driver.c
+++ b/crypto/test/kernel_driver.c
@@ -46,10 +46,12 @@
 #include <config.h>
 #endif
 
-#include <stdio.h> /* for printf() */
 #include "getopt_s.h"
 #include "crypto_kernel.h"
 
+#include <stdio.h> /* for printf() */
+#include <stdlib.h>
+
 void usage(char *prog_name)
 {
     printf("usage: %s [ -v ][ -d debug_module ]*\n", prog_name);
diff --git a/crypto/test/sha1_driver.c b/crypto/test/sha1_driver.c
index 90ef2ad99..858bedc8f 100644
--- a/crypto/test/sha1_driver.c
+++ b/crypto/test/sha1_driver.c
@@ -47,11 +47,13 @@
 #include <config.h>
 #endif
 
-#include <stdio.h>
-#include <string.h>
 #include "sha1.h"
 #include "util.h"
 
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
 #define SHA_PASS 0
 #define SHA_FAIL 1
 
diff --git a/include/srtp_priv.h b/include/srtp_priv.h
index 8fa4b08c3..b3244a010 100644
--- a/include/srtp_priv.h
+++ b/include/srtp_priv.h
@@ -51,7 +51,6 @@
 #include "srtp.h"
 #include "rdbx.h"
 #include "rdb.h"
-#include "integers.h"
 #include "cipher.h"
 #include "auth.h"
 #include "aes.h"
diff --git a/test/rdbx_driver.c b/test/rdbx_driver.c
index 399376380..f420134a7 100644
--- a/test/rdbx_driver.c
+++ b/test/rdbx_driver.c
@@ -46,12 +46,13 @@
 #include <config.h>
 #endif
 
-#include <stdio.h>    /* for printf()          */
 #include "getopt_s.h" /* for local getopt()    */
-
 #include "rdbx.h"
 #include "cipher_priv.h"
 
+#include <stdio.h> /* for printf()          */
+#include <stdlib.h>
+
 #ifdef ROC_TEST
 #error "srtp_rdbx_t won't work with ROC_TEST - bitmask same size as seq_median"
 #endif
diff --git a/test/replay_driver.c b/test/replay_driver.c
index 662b00a00..d751e7f9c 100644
--- a/test/replay_driver.c
+++ b/test/replay_driver.c
@@ -47,13 +47,13 @@
 #include <config.h>
 #endif
 
-#include <stdio.h>
-
 #include "rdb.h"
 #include "ut_sim.h"
-
 #include "cipher_priv.h"
 
+#include <stdio.h>
+#include <stdlib.h>
+
 /*
  * num_trials defines the number of trials that are used in the
  * validation functions below
diff --git a/test/roc_driver.c b/test/roc_driver.c
index 466a95628..1010fd0e3 100644
--- a/test/roc_driver.c
+++ b/test/roc_driver.c
@@ -60,6 +60,8 @@
 #include "rdbx.h"
 #include "ut_sim.h"
 
+#include <stdlib.h>
+
 srtp_err_status_t roc_test(size_t num_trials);
 
 int main(void)
diff --git a/test/rtp.c b/test/rtp.c
index 4c8ca571a..718e38c32 100644
--- a/test/rtp.c
+++ b/test/rtp.c
@@ -45,16 +45,16 @@
 
 #include "rtp.h"
 
+#include "cipher_priv.h"
+
 #include <stdio.h>
 #include <string.h>
-
+#include <stdlib.h>
 #include <sys/types.h>
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
 #endif
 
-#include "cipher_priv.h"
-
 #define PRINT_DEBUG 0   /* set to 1 to print out debugging data */
 #define VERBOSE_DEBUG 0 /* set to 1 to print out more data      */
 
diff --git a/test/rtp_decoder.c b/test/rtp_decoder.c
index 20023e390..6a413b8b9 100644
--- a/test/rtp_decoder.c
+++ b/test/rtp_decoder.c
@@ -63,12 +63,14 @@
  *
  */
 #include "getopt_s.h" /* for local getopt()  */
-#include <assert.h>   /* for assert()  */
 
 #include <pcap.h>
 #include "rtp_decoder.h"
 #include "util.h"
 
+#include <assert.h> /* for assert()  */
+#include <stdlib.h>
+
 #ifndef timersub
 #define timersub(a, b, result)                                                 \
     do {                                                                       \
diff --git a/test/ut_sim.c b/test/ut_sim.c
index 06f494910..02099cf7e 100644
--- a/test/ut_sim.c
+++ b/test/ut_sim.c
@@ -51,6 +51,8 @@
 #include "ut_sim.h"
 #include "cipher_priv.h"
 
+#include <stdlib.h>
+
 int ut_compar(const void *a, const void *b)
 {
     uint8_t r;
diff --git a/test/ut_sim.h b/test/ut_sim.h
index e678b5fdf..5462ccee2 100644
--- a/test/ut_sim.h
+++ b/test/ut_sim.h
@@ -47,7 +47,7 @@
 #ifndef UT_SIM_H
 #define UT_SIM_H
 
-#include "integers.h" /* for uint32_t */
+#include "datatypes.h"
 
 #ifdef __cplusplus
 extern "C" {