diff --git a/configure b/configure
index c6dcc8bfaa..b20df66363 100755
--- a/configure
+++ b/configure
@@ -24238,7 +24238,9 @@ _ACEOF
 fi
 
 
-if test x"$HAVE_LONG_INT_64" = x"no" ; then
+if test x"$HAVE_LONG_INT_64" = x"yes" ; then
+  pg_int64_type="long int"
+else
   { $as_echo "$as_me:$LINENO: checking whether long long int is 64 bits" >&5
 $as_echo_n "checking whether long long int is 64 bits... " >&6; }
 if test "${pgac_cv_type_long_long_int_64+set}" = set; then
@@ -24374,7 +24376,9 @@ _ACEOF
 
 fi
 
-  if test x"$HAVE_LONG_LONG_INT_64" = x"no" ; then
+  if test x"$HAVE_LONG_LONG_INT_64" = x"yes" ; then
+    pg_int64_type="long long int"
+  else
     { { $as_echo "$as_me:$LINENO: error: Cannot find a working 64-bit integer type." >&5
 $as_echo "$as_me: error: Cannot find a working 64-bit integer type." >&2;}
    { (exit 1); exit 1; }; }
@@ -24382,6 +24386,11 @@ $as_echo "$as_me: error: Cannot find a working 64-bit integer type." >&2;}
 fi
 
 
+cat >>confdefs.h <<_ACEOF
+#define PG_INT64_TYPE $pg_int64_type
+_ACEOF
+
+
 
 if test x"$HAVE_LONG_LONG_INT_64" = xyes ; then
   cat >conftest.$ac_ext <<_ACEOF
@@ -29930,6 +29939,9 @@ fi
 ac_config_headers="$ac_config_headers src/include/pg_config.h"
 
 
+ac_config_headers="$ac_config_headers src/include/pg_config_ext.h"
+
+
 ac_config_headers="$ac_config_headers src/interfaces/ecpg/include/ecpg_config.h"
 
 
@@ -30550,6 +30562,7 @@ do
     "src/Makefile.port") CONFIG_LINKS="$CONFIG_LINKS src/Makefile.port:src/makefiles/Makefile.${template}" ;;
     "check_win32_symlinks") CONFIG_COMMANDS="$CONFIG_COMMANDS check_win32_symlinks" ;;
     "src/include/pg_config.h") CONFIG_HEADERS="$CONFIG_HEADERS src/include/pg_config.h" ;;
+    "src/include/pg_config_ext.h") CONFIG_HEADERS="$CONFIG_HEADERS src/include/pg_config_ext.h" ;;
     "src/interfaces/ecpg/include/ecpg_config.h") CONFIG_HEADERS="$CONFIG_HEADERS src/interfaces/ecpg/include/ecpg_config.h" ;;
 
   *) { { $as_echo "$as_me:$LINENO: error: invalid argument: $ac_config_target" >&5
@@ -31220,6 +31233,10 @@ $as_echo "$as_me: WARNING: *** link for $FILE -- please fix by hand" >&2;}
     "src/include/pg_config.h":H)
 # Update timestamp for pg_config.h (see Makefile.global)
 echo >src/include/stamp-h
+ ;;
+    "src/include/pg_config_ext.h":H)
+# Update timestamp for pg_config_ext.h (see Makefile.global)
+echo >src/include/stamp-ext-h
  ;;
     "src/interfaces/ecpg/include/ecpg_config.h":H) echo >src/interfaces/ecpg/include/stamp-h ;;
 
diff --git a/configure.in b/configure.in
index fef8e7f013..2dee4b392b 100644
--- a/configure.in
+++ b/configure.in
@@ -1580,13 +1580,19 @@ dnl 64-bit type.  But we still handle the case of snprintf being broken.
 
 PGAC_TYPE_64BIT_INT([long int])
 
-if test x"$HAVE_LONG_INT_64" = x"no" ; then
+if test x"$HAVE_LONG_INT_64" = x"yes" ; then
+  pg_int64_type="long int"
+else
   PGAC_TYPE_64BIT_INT([long long int])
-  if test x"$HAVE_LONG_LONG_INT_64" = x"no" ; then
+  if test x"$HAVE_LONG_LONG_INT_64" = x"yes" ; then
+    pg_int64_type="long long int"
+  else
     AC_MSG_ERROR([Cannot find a working 64-bit integer type.])
   fi
 fi
 
+AC_DEFINE_UNQUOTED(PG_INT64_TYPE, $pg_int64_type,
+  [Define to the name of a signed 64-bit integer type.])
 
 dnl If we need to use "long long int", figure out whether nnnLL notation works.
 
@@ -1935,6 +1941,12 @@ AC_CONFIG_HEADERS([src/include/pg_config.h],
 echo >src/include/stamp-h
 ])
 
+AC_CONFIG_HEADERS([src/include/pg_config_ext.h],
+[
+# Update timestamp for pg_config_ext.h (see Makefile.global)
+echo >src/include/stamp-ext-h
+])
+
 AC_CONFIG_HEADERS([src/interfaces/ecpg/include/ecpg_config.h],
                   [echo >src/interfaces/ecpg/include/stamp-h])
 
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 1e3b401147..000bfd772a 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -539,6 +539,12 @@ $(top_builddir)/src/include/pg_config.h: $(top_builddir)/src/include/stamp-h ;
 $(top_builddir)/src/include/stamp-h: $(top_srcdir)/src/include/pg_config.h.in $(top_builddir)/config.status
 	cd $(top_builddir) && ./config.status src/include/pg_config.h
 
+# Also remake pg_config_ext.h from pg_config_ext.h.in, same logic as above.
+$(top_builddir)/src/include/pg_config_ext.h: $(top_builddir)/src/include/stamp-ext-h ;
+
+$(top_builddir)/src/include/stamp-ext-h: $(top_srcdir)/src/include/pg_config_ext.h.in $(top_builddir)/config.status
+	cd $(top_builddir) && ./config.status src/include/pg_config_ext.h
+
 # Also remake ecpg_config.h from ecpg_config.h.in if the latter changed, same
 # logic as above.
 $(top_builddir)/src/interfaces/ecpg/include/ecpg_config.h: $(top_builddir)/src/interfaces/ecpg/include/stamp-h ;
diff --git a/src/bcc32.mak b/src/bcc32.mak
index 83c26df167..c691924163 100644
--- a/src/bcc32.mak
+++ b/src/bcc32.mak
@@ -26,6 +26,7 @@ NULL=nul
 ALL:
    cd include
    if not exist pg_config.h copy pg_config.h.win32 pg_config.h
+   if not exist pg_config_ext.h copy pg_config_ext.h.win32 pg_config_ext.h
    if not exist pg_config_os.h copy port\win32.h pg_config_os.h
    cd ..
    cd interfaces\libpq
@@ -42,5 +43,5 @@ CLEAN:
 
 DISTCLEAN: CLEAN
    cd include
-   del pg_config.h pg_config_os.h
+   del pg_config.h pg_config_ext.h pg_config_os.h
    cd ..
diff --git a/src/include/.gitignore b/src/include/.gitignore
index fa285a1605..49d108dbed 100644
--- a/src/include/.gitignore
+++ b/src/include/.gitignore
@@ -1,5 +1,6 @@
 /stamp-h
+/stamp-ext-h
 /pg_config.h
+/pg_config_ext.h
 /pg_config_os.h
 /dynloader.h
-
diff --git a/src/include/Makefile b/src/include/Makefile
index 35d217cf0c..7e31a1e039 100644
--- a/src/include/Makefile
+++ b/src/include/Makefile
@@ -13,7 +13,7 @@ top_builddir = ../..
 include $(top_builddir)/src/Makefile.global
 
 
-all: pg_config.h pg_config_os.h
+all: pg_config.h pg_config_ext.h pg_config_os.h
 
 
 # Subdirectories containing headers for server-side dev
@@ -29,8 +29,9 @@ install: all installdirs
 # These headers are needed by the public headers of the interfaces.
 	$(INSTALL_DATA) $(srcdir)/postgres_ext.h   '$(DESTDIR)$(includedir)'
 	$(INSTALL_DATA) $(srcdir)/libpq/libpq-fs.h '$(DESTDIR)$(includedir)/libpq'
-	$(INSTALL_DATA) pg_config.h    '$(DESTDIR)$(includedir)'
-	$(INSTALL_DATA) pg_config_os.h '$(DESTDIR)$(includedir)'
+	$(INSTALL_DATA) pg_config.h     '$(DESTDIR)$(includedir)'
+	$(INSTALL_DATA) pg_config_ext.h '$(DESTDIR)$(includedir)'
+	$(INSTALL_DATA) pg_config_os.h  '$(DESTDIR)$(includedir)'
 	$(INSTALL_DATA) $(srcdir)/pg_config_manual.h '$(DESTDIR)$(includedir)'
 # These headers are needed by the not-so-public headers of the interfaces.
 	$(INSTALL_DATA) $(srcdir)/c.h            '$(DESTDIR)$(includedir_internal)'
@@ -38,8 +39,9 @@ install: all installdirs
 	$(INSTALL_DATA) $(srcdir)/postgres_fe.h  '$(DESTDIR)$(includedir_internal)'
 	$(INSTALL_DATA) $(srcdir)/libpq/pqcomm.h '$(DESTDIR)$(includedir_internal)/libpq'
 # These headers are needed for server-side development
-	$(INSTALL_DATA) pg_config.h    '$(DESTDIR)$(includedir_server)'
-	$(INSTALL_DATA) pg_config_os.h '$(DESTDIR)$(includedir_server)'
+	$(INSTALL_DATA) pg_config.h     '$(DESTDIR)$(includedir_server)'
+	$(INSTALL_DATA) pg_config_ext.h '$(DESTDIR)$(includedir_server)'
+	$(INSTALL_DATA) pg_config_os.h  '$(DESTDIR)$(includedir_server)'
 	$(INSTALL_DATA) utils/errcodes.h '$(DESTDIR)$(includedir_server)/utils'
 	$(INSTALL_DATA) utils/fmgroids.h '$(DESTDIR)$(includedir_server)/utils'
 # We don't use INSTALL_DATA for performance reasons --- there are a lot of files
@@ -62,7 +64,7 @@ installdirs:
 
 
 uninstall:
-	rm -f $(addprefix '$(DESTDIR)$(includedir)'/, pg_config.h pg_config_os.h pg_config_manual.h postgres_ext.h libpq/libpq-fs.h)
+	rm -f $(addprefix '$(DESTDIR)$(includedir)'/, pg_config.h pg_config_ext.h pg_config_os.h pg_config_manual.h postgres_ext.h libpq/libpq-fs.h)
 	rm -f $(addprefix '$(DESTDIR)$(includedir_internal)'/, c.h port.h postgres_fe.h libpq/pqcomm.h)
 # heuristic...
 	rm -rf $(addprefix '$(DESTDIR)$(includedir_server)'/, $(SUBDIRS) *.h)
@@ -72,7 +74,7 @@ clean:
 	rm -f utils/fmgroids.h utils/errcodes.h parser/gram.h utils/probes.h catalog/schemapg.h
 
 distclean maintainer-clean: clean
-	rm -f pg_config.h dynloader.h pg_config_os.h stamp-h
+	rm -f pg_config.h pg_config_ext.h pg_config_os.h dynloader.h stamp-h stamp-ext-h
 
 maintainer-check:
 	cd catalog && ./duplicate_oids
diff --git a/src/include/c.h b/src/include/c.h
index bec1eb3da4..127b5d94e3 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -44,19 +44,17 @@
 #ifndef C_H
 #define C_H
 
-/*
- * We have to include stdlib.h here because it defines many of these macros
- * on some platforms, and we only want our definitions used if stdlib.h doesn't
- * have its own.  The same goes for stddef and stdarg if present.
- */
+#include "postgres_ext.h"
+
+/* Must undef pg_config_ext.h symbols before including pg_config.h */
+#undef PG_INT64_TYPE
 
 #include "pg_config.h"
 #include "pg_config_manual.h"	/* must be after pg_config.h */
-#if !defined(WIN32) && !defined(__CYGWIN__)		/* win32 will include further
-												 * down */
+
+#if !defined(WIN32) && !defined(__CYGWIN__)	/* win32 includes further down */
 #include "pg_config_os.h"		/* must be before any system header files */
 #endif
-#include "postgres_ext.h"
 
 #if _MSC_VER >= 1400 || defined(HAVE_CRTDEFS_H)
 #define errcode __msvc_errcode
@@ -64,6 +62,12 @@
 #undef errcode
 #endif
 
+/*
+ * We have to include stdlib.h here because it defines many of these macros
+ * on some platforms, and we only want our definitions used if stdlib.h doesn't
+ * have its own.  The same goes for stddef and stdarg if present.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 58cd5907dd..61ae0c26b8 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -671,6 +671,9 @@
 /* Define to the version of this package. */
 #undef PACKAGE_VERSION
 
+/* Define to the name of a signed 64-bit integer type. */
+#undef PG_INT64_TYPE
+
 /* Define to the name of the default PostgreSQL service principal in Kerberos.
    (--with-krb-srvnam=NAME) */
 #undef PG_KRB_SRVNAM
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 4d9cc55c69..3715dbdca1 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -562,6 +562,9 @@
 /* Define to the version of this package. */
 #define PACKAGE_VERSION "9.3devel"
 
+/* Define to the name of a signed 64-bit integer type. */
+#define PG_INT64_TYPE long long int
+
 /* PostgreSQL version as a string */
 #define PG_VERSION "9.3devel"
 
diff --git a/src/include/pg_config_ext.h.in b/src/include/pg_config_ext.h.in
new file mode 100644
index 0000000000..8acadbdafd
--- /dev/null
+++ b/src/include/pg_config_ext.h.in
@@ -0,0 +1,7 @@
+/*
+ * src/include/pg_config_ext.h.in.  This is generated manually, not by
+ * autoheader, since we want to limit which symbols get defined here.
+ */
+
+/* Define to the name of a signed 64-bit integer type. */
+#undef PG_INT64_TYPE
diff --git a/src/include/pg_config_ext.h.win32 b/src/include/pg_config_ext.h.win32
new file mode 100644
index 0000000000..65bbb5d80d
--- /dev/null
+++ b/src/include/pg_config_ext.h.win32
@@ -0,0 +1,7 @@
+/*
+ * src/include/pg_config_ext.h.win32.  This is generated manually, not by
+ * autoheader, since we want to limit which symbols get defined here.
+ */
+
+/* Define to the name of a signed 64-bit integer type. */
+#define PG_INT64_TYPE long long int
diff --git a/src/include/postgres_ext.h b/src/include/postgres_ext.h
index 76502de647..5ba379f869 100644
--- a/src/include/postgres_ext.h
+++ b/src/include/postgres_ext.h
@@ -23,6 +23,8 @@
 #ifndef POSTGRES_EXT_H
 #define POSTGRES_EXT_H
 
+#include "pg_config_ext.h"
+
 /*
  * Object ID is a fundamental type in Postgres.
  */
@@ -37,6 +39,9 @@ typedef unsigned int Oid;
 #define OID_MAX  UINT_MAX
 /* you will need to include <limits.h> to use the above #define */
 
+/* Define a signed 64-bit integer type for use in client API declarations. */
+typedef PG_INT64_TYPE pg_int64;
+
 
 /*
  * Identifiers of error message fields.  Kept here to keep common
@@ -56,9 +61,4 @@ typedef unsigned int Oid;
 #define PG_DIAG_SOURCE_LINE		'L'
 #define PG_DIAG_SOURCE_FUNCTION 'R'
 
-#ifndef NO_PG_INT64
-#define HAVE_PG_INT64 1
-typedef long long int pg_int64;
-#endif
-
-#endif
+#endif   /* POSTGRES_EXT_H */
diff --git a/src/include/storage/large_object.h b/src/include/storage/large_object.h
index 715f0c3bc4..f8232411a7 100644
--- a/src/include/storage/large_object.h
+++ b/src/include/storage/large_object.h
@@ -62,10 +62,13 @@ typedef struct LargeObjectDesc
  * This avoids unnecessary tuple updates caused by partial-page writes.
  */
 #define LOBLKSIZE		(BLCKSZ / 4)
+
 /*
- * Maximum byte length for each large object
-*/
-#define MAX_LARGE_OBJECT_SIZE	((int64)INT_MAX * LOBLKSIZE)
+ * Maximum length in bytes for a large object.  To make this larger, we'd
+ * have to widen pg_largeobject.pageno as well as various internal variables.
+ */
+#define MAX_LARGE_OBJECT_SIZE	((int64) INT_MAX * LOBLKSIZE)
+
 
 /*
  * Function definitions...
@@ -77,8 +80,8 @@ extern Oid	inv_create(Oid lobjId);
 extern LargeObjectDesc *inv_open(Oid lobjId, int flags, MemoryContext mcxt);
 extern void inv_close(LargeObjectDesc *obj_desc);
 extern int	inv_drop(Oid lobjId);
-extern int64	inv_seek(LargeObjectDesc *obj_desc, int64 offset, int whence);
-extern int64	inv_tell(LargeObjectDesc *obj_desc);
+extern int64 inv_seek(LargeObjectDesc *obj_desc, int64 offset, int whence);
+extern int64 inv_tell(LargeObjectDesc *obj_desc);
 extern int	inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes);
 extern int	inv_write(LargeObjectDesc *obj_desc, const char *buf, int nbytes);
 extern void inv_truncate(LargeObjectDesc *obj_desc, int64 len);
diff --git a/src/interfaces/libpq/bcc32.mak b/src/interfaces/libpq/bcc32.mak
index fbef737ecd..441fb5e76f 100644
--- a/src/interfaces/libpq/bcc32.mak
+++ b/src/interfaces/libpq/bcc32.mak
@@ -153,11 +153,14 @@ LIB32_OBJS= \
 	"$(INTDIR)\pthread-win32.obj"
 
 
-config: ..\..\include\pg_config.h ..\..\include\pg_config_os.h pg_config_paths.h
+config: ..\..\include\pg_config.h ..\..\include\pg_config_ext.h ..\..\include\pg_config_os.h pg_config_paths.h
 
 ..\..\include\pg_config.h: ..\..\include\pg_config.h.win32
 	copy ..\..\include\pg_config.h.win32 ..\..\include\pg_config.h
 
+..\..\include\pg_config_ext.h: ..\..\include\pg_config_ext.h.win32
+	copy ..\..\include\pg_config_ext.h.win32 ..\..\include\pg_config_ext.h
+
 ..\..\include\pg_config_os.h: ..\..\include\port\win32.h
 	copy ..\..\include\port\win32.h ..\..\include\pg_config_os.h
 
diff --git a/src/interfaces/libpq/fe-lobj.c b/src/interfaces/libpq/fe-lobj.c
index 022cfec093..7c40100b86 100644
--- a/src/interfaces/libpq/fe-lobj.c
+++ b/src/interfaces/libpq/fe-lobj.c
@@ -187,7 +187,6 @@ lo_truncate(PGconn *conn, int fd, size_t len)
  * returns 0 upon success
  * returns -1 upon failure
  */
-#ifdef HAVE_PG_INT64
 int
 lo_truncate64(PGconn *conn, int fd, pg_int64 len)
 {
@@ -232,7 +231,6 @@ lo_truncate64(PGconn *conn, int fd, pg_int64 len)
 		return -1;
 	}
 }
-#endif
 
 /*
  * lo_read
@@ -325,10 +323,7 @@ lo_write(PGconn *conn, int fd, const char *buf, size_t len)
 /*
  * lo_lseek
  *	  change the current read or write location on a large object
- * currently, only L_SET is a legal value for whence
- *
  */
-
 int
 lo_lseek(PGconn *conn, int fd, int offset, int whence)
 {
@@ -372,11 +367,7 @@ lo_lseek(PGconn *conn, int fd, int offset, int whence)
 /*
  * lo_lseek64
  *	  change the current read or write location on a large object
- * currently, only L_SET is a legal value for whence
- *
  */
-
-#ifdef HAVE_PG_INT64
 pg_int64
 lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence)
 {
@@ -424,7 +415,6 @@ lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence)
 		return -1;
 	}
 }
-#endif
 
 /*
  * lo_creat
@@ -554,9 +544,7 @@ lo_tell(PGconn *conn, int fd)
 /*
  * lo_tell64
  *	  returns the current seek location of the large object
- *
  */
-#ifdef HAVE_PG_INT64
 pg_int64
 lo_tell64(PGconn *conn, int fd)
 {
@@ -595,12 +583,10 @@ lo_tell64(PGconn *conn, int fd)
 		return -1;
 	}
 }
-#endif
 
 /*
  * lo_unlink
  *	  delete a file
- *
  */
 
 int
@@ -1031,6 +1017,7 @@ lo_initialize(PGconn *conn)
 			return -1;
 		}
 	}
+
 	/*
 	 * Put the structure into the connection control
 	 */
diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index 73568ca23c..0b8d9a6813 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -507,24 +507,21 @@ extern unsigned char *PQescapeBytea(const unsigned char *from, size_t from_lengt
 
 /* === in fe-print.c === */
 
-extern void
-PQprint(FILE *fout,				/* output stream */
+extern void PQprint(FILE *fout,				/* output stream */
 		const PGresult *res,
 		const PQprintOpt *ps);	/* option structure */
 
 /*
  * really old printing routines
  */
-extern void
-PQdisplayTuples(const PGresult *res,
+extern void PQdisplayTuples(const PGresult *res,
 				FILE *fp,		/* where to send the output */
 				int fillAlign,	/* pad the fields with spaces */
 				const char *fieldSep,	/* field separator */
 				int printHeader,	/* display headers? */
 				int quiet);
 
-extern void
-PQprintTuples(const PGresult *res,
+extern void PQprintTuples(const PGresult *res,
 			  FILE *fout,		/* output stream */
 			  int printAttName, /* print attribute names */
 			  int terseOutput,	/* delimiter bars */
@@ -539,21 +536,18 @@ extern int	lo_close(PGconn *conn, int fd);
 extern int	lo_read(PGconn *conn, int fd, char *buf, size_t len);
 extern int	lo_write(PGconn *conn, int fd, const char *buf, size_t len);
 extern int	lo_lseek(PGconn *conn, int fd, int offset, int whence);
+extern pg_int64 lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence);
 extern Oid	lo_creat(PGconn *conn, int mode);
 extern Oid	lo_create(PGconn *conn, Oid lobjId);
 extern int	lo_tell(PGconn *conn, int fd);
+extern pg_int64 lo_tell64(PGconn *conn, int fd);
 extern int	lo_truncate(PGconn *conn, int fd, size_t len);
+extern int	lo_truncate64(PGconn *conn, int fd, pg_int64 len);
 extern int	lo_unlink(PGconn *conn, Oid lobjId);
 extern Oid	lo_import(PGconn *conn, const char *filename);
 extern Oid	lo_import_with_oid(PGconn *conn, const char *filename, Oid lobjId);
 extern int	lo_export(PGconn *conn, Oid lobjId, const char *filename);
 
-#ifdef HAVE_PG_INT64
-extern pg_int64	lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence);
-extern pg_int64	lo_tell64(PGconn *conn, int fd);
-extern int	lo_truncate64(PGconn *conn, int fd, pg_int64 len);
-#endif
-
 /* === in fe-misc.c === */
 
 /* Get the version of the libpq library in use */
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 375821e017..f420476ad2 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -271,11 +271,11 @@ typedef struct pgLobjfuncs
 	Oid			fn_lo_create;	/* OID of backend function lo_create	*/
 	Oid			fn_lo_unlink;	/* OID of backend function lo_unlink	*/
 	Oid			fn_lo_lseek;	/* OID of backend function lo_lseek		*/
-	Oid			fn_lo_lseek64;	/* OID of backend function lo_lseek64		*/
+	Oid			fn_lo_lseek64;	/* OID of backend function lo_lseek64	*/
 	Oid			fn_lo_tell;		/* OID of backend function lo_tell		*/
-	Oid			fn_lo_tell64;		/* OID of backend function lo_tell64		*/
+	Oid			fn_lo_tell64;	/* OID of backend function lo_tell64	*/
 	Oid			fn_lo_truncate; /* OID of backend function lo_truncate	*/
-	Oid			fn_lo_truncate64; /* OID of backend function lo_truncate64	*/
+	Oid			fn_lo_truncate64;		/* OID of function lo_truncate64 */
 	Oid			fn_lo_read;		/* OID of backend function LOread		*/
 	Oid			fn_lo_write;	/* OID of backend function LOwrite		*/
 } PGlobjfuncs;
diff --git a/src/interfaces/libpq/win32.mak b/src/interfaces/libpq/win32.mak
index 70a741a5f4..9355de23ce 100644
--- a/src/interfaces/libpq/win32.mak
+++ b/src/interfaces/libpq/win32.mak
@@ -164,11 +164,14 @@ LIB32_OBJS= \
 	"$(INTDIR)\pthread-win32.obj"
 
 
-config: ..\..\include\pg_config.h pg_config_paths.h  ..\..\include\pg_config_os.h
+config: ..\..\include\pg_config.h ..\..\include\pg_config_ext.h pg_config_paths.h  ..\..\include\pg_config_os.h
 
 ..\..\include\pg_config.h: ..\..\include\pg_config.h.win32
 	copy ..\..\include\pg_config.h.win32 ..\..\include\pg_config.h
 
+..\..\include\pg_config_ext.h: ..\..\include\pg_config_ext.h.win32
+	copy ..\..\include\pg_config_ext.h.win32 ..\..\include\pg_config_ext.h
+
 ..\..\include\pg_config_os.h:
 	copy ..\..\include\port\win32.h ..\..\include\pg_config_os.h
 
diff --git a/src/tools/msvc/Install.pm b/src/tools/msvc/Install.pm
index 235a1504fa..6036714e7c 100644
--- a/src/tools/msvc/Install.pm
+++ b/src/tools/msvc/Install.pm
@@ -490,7 +490,8 @@ sub CopyIncludeFiles
 	CopyFiles(
 		'Public headers',
 		$target . '/include/',
-		'src/include/', 'postgres_ext.h', 'pg_config.h', 'pg_config_os.h',
+		'src/include/', 'postgres_ext.h',
+		'pg_config.h', 'pg_config_ext.h', 'pg_config_os.h',
 		'pg_config_manual.h');
 	lcopy('src/include/libpq/libpq-fs.h', $target . '/include/libpq/')
 	  || croak 'Could not copy libpq-fs.h';
@@ -514,7 +515,7 @@ sub CopyIncludeFiles
 	CopyFiles(
 		'Server headers',
 		$target . '/include/server/',
-		'src/include/', 'pg_config.h', 'pg_config_os.h');
+		'src/include/', 'pg_config.h', 'pg_config_ext.h', 'pg_config_os.h');
 	CopyFiles(
 		'Grammar header',
 		$target . '/include/server/parser/',
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index d6b79dcc29..d7dbc5de5c 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -242,6 +242,14 @@ s{PG_VERSION_STR "[^"]+"}{__STRINGIFY(x) #x\n#define __STRINGIFY2(z) __STRINGIFY
 		close(I);
 	}
 
+	if (IsNewer(
+			"src\\include\\pg_config_ext.h", "src\\include\\pg_config_ext.h.win32"))
+	{
+		print "Copying pg_config_ext.h...\n";
+		copyFile("src\\include\\pg_config_ext.h.win32",
+			"src\\include\\pg_config_ext.h");
+	}
+
 	$self->GenerateDefFile(
 		"src\\interfaces\\libpq\\libpqdll.def",
 		"src\\interfaces\\libpq\\exports.txt",
diff --git a/src/tools/msvc/clean.bat b/src/tools/msvc/clean.bat
index ac310382e3..a2622ba2e4 100755
--- a/src/tools/msvc/clean.bat
+++ b/src/tools/msvc/clean.bat
@@ -22,6 +22,7 @@ if exist src\backend\win32ver.rc del /q src\backend\win32ver.rc
 
 REM Delete files created with GenerateFiles() in Solution.pm
 if exist src\include\pg_config.h del /q src\include\pg_config.h
+if exist src\include\pg_config_ext.h del /q src\include\pg_config_ext.h
 if exist src\include\pg_config_os.h del /q src\include\pg_config_os.h
 if %DIST%==1 if exist src\backend\parser\gram.h del /q src\backend\parser\gram.h
 if exist src\include\utils\errcodes.h del /q src\include\utils\errcodes.h
diff --git a/src/win32.mak b/src/win32.mak
index 7bbc988ff6..9699e81003 100644
--- a/src/win32.mak
+++ b/src/win32.mak
@@ -12,6 +12,7 @@ NULL=nul
 ALL:
    cd include
    if not exist pg_config.h copy pg_config.h.win32 pg_config.h
+   if not exist pg_config_ext.h copy pg_config_ext.h.win32 pg_config_ext.h
    if not exist pg_config_os.h copy port\win32.h pg_config_os.h
    cd ..
    cd interfaces\libpq
@@ -27,5 +28,5 @@ CLEAN:
 
 DISTCLEAN: CLEAN
    cd include
-   del pg_config.h pg_config_os.h
+   del pg_config.h pg_config_ext.h pg_config_os.h
    cd ..