diff --git a/configure b/configure
index 85805e9f571d38cfe877a203c5a849d010865b4a..ae34179e0d9e698cbd5226e5785469848ba37935 100755
--- a/configure
+++ b/configure
@@ -10116,10 +10116,7 @@ done
 
 
 
-
-
-
-for ac_header in crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h poll.h pwd.h sys/ioctl.h sys/ipc.h sys/poll.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/socket.h sys/sockio.h sys/tas.h sys/time.h sys/ucred.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h kernel/OS.h kernel/image.h SupportDefs.h
+for ac_header in crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h poll.h pwd.h sys/ioctl.h sys/ipc.h sys/poll.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/socket.h sys/sockio.h sys/tas.h sys/time.h sys/ucred.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h
 do
 as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 if { as_var=$as_ac_Header; eval "test \"\${$as_var+set}\" = set"; }; then
@@ -27696,9 +27693,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -27734,9 +27728,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -27806,9 +27797,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -27844,9 +27832,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -27916,9 +27901,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -27954,9 +27936,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -28026,9 +28005,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
@@ -28064,9 +28040,6 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 int
 main ()
diff --git a/configure.in b/configure.in
index 926a399f09e8636707ef5b7ad46f576adfd4cf62..d064d5c19ed225495f5e43a9bb2dc9ad77f56e07 100644
--- a/configure.in
+++ b/configure.in
@@ -971,7 +971,7 @@ AC_SUBST(OSSP_UUID_LIBS)
 ##
 
 dnl sys/socket.h is required by AC_FUNC_ACCEPT_ARGTYPES
-AC_CHECK_HEADERS([crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h poll.h pwd.h sys/ioctl.h sys/ipc.h sys/poll.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/socket.h sys/sockio.h sys/tas.h sys/time.h sys/ucred.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h kernel/OS.h kernel/image.h SupportDefs.h])
+AC_CHECK_HEADERS([crypt.h dld.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h poll.h pwd.h sys/ioctl.h sys/ipc.h sys/poll.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/socket.h sys/sockio.h sys/tas.h sys/time.h sys/ucred.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h])
 
 # On BSD, cpp test for net/if.h will fail unless sys/socket.h
 # is included first.
@@ -1719,10 +1719,7 @@ AC_DEFINE_UNQUOTED(MAXIMUM_ALIGNOF, $MAX_ALIGNOF, [Define as the maximum alignme
 # Some platforms predefine the types int8, int16, etc.  Only check
 # a (hopefully) representative subset.
 AC_CHECK_TYPES([int8, uint8, int64, uint64], [], [],
-[#include <stdio.h>
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif])
+[#include <stdio.h>])
 
 # We also check for sig_atomic_t, which *should* be defined per ANSI
 # C, but is missing on some old platforms.
diff --git a/src/backend/port/sysv_sema.c b/src/backend/port/sysv_sema.c
index 5d7907e1002a18d6d56889638ba3db336cc2046a..08803552ca5c19ea013cf019b5d93b244b556b8c 100644
--- a/src/backend/port/sysv_sema.c
+++ b/src/backend/port/sysv_sema.c
@@ -23,9 +23,6 @@
 #ifdef HAVE_SYS_SEM_H
 #include <sys/sem.h>
 #endif
-#ifdef HAVE_KERNEL_OS_H
-#include <kernel/OS.h>
-#endif
 
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c
index 2eab80aef7be4a22da33c16c28ac87c2b67f842d..b28766c652e9bba21f60f1a4cc2ae627c55b2a14 100644
--- a/src/backend/port/sysv_shmem.c
+++ b/src/backend/port/sysv_shmem.c
@@ -26,9 +26,6 @@
 #ifdef HAVE_SYS_SHM_H
 #include <sys/shm.h>
 #endif
-#ifdef HAVE_KERNEL_OS_H
-#include <kernel/OS.h>
-#endif
 
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/include/c.h b/src/include/c.h
index 96375ab567c339f19924d1a15e9a26ad214b6d57..8b3c5e59967af894478cb28006af8f7b526a00aa 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -81,9 +81,6 @@
 #if defined(WIN32) || defined(__CYGWIN__)
 #include <fcntl.h>				/* ensure O_BINARY is available */
 #endif
-#ifdef HAVE_SUPPORTDEFS_H
-#include <SupportDefs.h>
-#endif
 
 #if defined(WIN32) || defined(__CYGWIN__)
 /* We have to redefine some system functions after they are included above. */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 6bf865f813b658dc6eed1debb8eed50882426cb6..fa9ebde14e37056cb25978a66ada2ac328f6f216 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -269,12 +269,6 @@
 /* Define to 1 if you have isinf(). */
 #undef HAVE_ISINF
 
-/* Define to 1 if you have the <kernel/image.h> header file. */
-#undef HAVE_KERNEL_IMAGE_H
-
-/* Define to 1 if you have the <kernel/OS.h> header file. */
-#undef HAVE_KERNEL_OS_H
-
 /* Define to 1 if `e_data' is member of `krb5_error'. */
 #undef HAVE_KRB5_ERROR_E_DATA
 
@@ -526,9 +520,6 @@
 /* Define to 1 if `tm_zone' is member of `struct tm'. */
 #undef HAVE_STRUCT_TM_TM_ZONE
 
-/* Define to 1 if you have the <SupportDefs.h> header file. */
-#undef HAVE_SUPPORTDEFS_H
-
 /* Define to 1 if you have the `symlink' function. */
 #undef HAVE_SYMLINK
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 1ca6b0a95930ea86dfc71ab151ae97f05a07013a..614c1e49cfeab4fb86b3e0e6e61e10d140b2524b 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -193,12 +193,6 @@
 /* Define to 1 if you have isinf(). */
 #define HAVE_ISINF 1
 
-/* Define to 1 if you have the <kernel/image.h> header file. */
-/* #undef HAVE_KERNEL_IMAGE_H */
-
-/* Define to 1 if you have the <kernel/OS.h> header file. */
-/* #undef HAVE_KERNEL_OS_H */
-
 /* Define to 1 if `e_data' is member of `krb5_error'. */
 /* #undef HAVE_KRB5_ERROR_E_DATA */
 
@@ -423,9 +417,6 @@
 /* Define to 1 if `tm_zone' is member of `struct tm'. */
 /* #undef HAVE_STRUCT_TM_TM_ZONE */
 
-/* Define to 1 if you have the <SupportDefs.h> header file. */
-/* #undef HAVE_SUPPORTDEFS_H */
-
 /* Define to 1 if you have the `symlink' function. */
 #define HAVE_SYMLINK 1