diff --git a/lib/common/mem.h b/lib/common/mem.h
index c8361ab10..4728ef767 100644
--- a/lib/common/mem.h
+++ b/lib/common/mem.h
@@ -45,7 +45,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
-# include <stdint.h>
+#  if defined(_AIX)
+#    include <inttypes.h>
+#  else
+#    include <stdint.h> /* intptr_t */
+#  endif
   typedef   uint8_t BYTE;
   typedef  uint16_t U16;
   typedef   int16_t S16;
diff --git a/lib/legacy/zstd_v01.c b/lib/legacy/zstd_v01.c
index eb2362833..13115bec5 100644
--- a/lib/legacy/zstd_v01.c
+++ b/lib/legacy/zstd_v01.c
@@ -1280,7 +1280,11 @@ static size_t HUF_decompress (void* dst, size_t maxDstSize, const void* cSrc, si
 *  Basic Types
 *********************************************************/
 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
 typedef  uint8_t BYTE;
 typedef uint16_t U16;
 typedef  int16_t S16;
diff --git a/lib/legacy/zstd_v02.c b/lib/legacy/zstd_v02.c
index 32d45a6d4..9abb6d033 100644
--- a/lib/legacy/zstd_v02.c
+++ b/lib/legacy/zstd_v02.c
@@ -89,7 +89,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
diff --git a/lib/legacy/zstd_v03.c b/lib/legacy/zstd_v03.c
index b541eae2a..a19cb205a 100644
--- a/lib/legacy/zstd_v03.c
+++ b/lib/legacy/zstd_v03.c
@@ -90,7 +90,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
diff --git a/lib/legacy/zstd_v04.c b/lib/legacy/zstd_v04.c
index 19fda8980..77d52555b 100644
--- a/lib/legacy/zstd_v04.c
+++ b/lib/legacy/zstd_v04.c
@@ -52,7 +52,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
diff --git a/lib/legacy/zstd_v05.c b/lib/legacy/zstd_v05.c
index 243d22256..ca8d5c9bf 100644
--- a/lib/legacy/zstd_v05.c
+++ b/lib/legacy/zstd_v05.c
@@ -80,7 +80,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
diff --git a/lib/legacy/zstd_v06.c b/lib/legacy/zstd_v06.c
index c56f58277..c4ac7dba8 100644
--- a/lib/legacy/zstd_v06.c
+++ b/lib/legacy/zstd_v06.c
@@ -82,7 +82,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
diff --git a/lib/legacy/zstd_v07.c b/lib/legacy/zstd_v07.c
index 9f3a597f1..049ba4749 100644
--- a/lib/legacy/zstd_v07.c
+++ b/lib/legacy/zstd_v07.c
@@ -242,7 +242,11 @@ extern "C" {
 *  Basic Types
 *****************************************************************/
 #if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
diff --git a/programs/timefn.h b/programs/timefn.h
index eb3c13093..5d2818e8a 100644
--- a/programs/timefn.h
+++ b/programs/timefn.h
@@ -28,7 +28,11 @@ extern "C" {
 ******************************************/
 
 #if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
-# include <stdint.h>
+# if defined(_AIX)
+#  include <inttypes.h>
+# else
+#  include <stdint.h> /* intptr_t */
+# endif
   typedef uint64_t           PTime;  /* Precise Time */
 #else
   typedef unsigned long long PTime;  /* does not support compilers without long long support */