diff --git a/configure b/configure
index cc098aabdbc..2821a8f7e4a 100755
--- a/configure
+++ b/configure
@@ -13726,24 +13726,6 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
-
-if test x"$HAVE_LONG_LONG_INT_64" = xyes ; then
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-#define INT64CONST(x)  x##LL
-long long int foo = INT64CONST(0x1234567890123456);
-
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-
-$as_echo "#define HAVE_LL_CONSTANTS 1" >>confdefs.h
-
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-
-
 # If we found "long int" is 64 bits, assume snprintf handles it.  If
 # we found we need to use "long long int", better check.  We cope with
 # snprintfs that use %lld, %qd, or %I64d as the format.  If none of these
diff --git a/configure.in b/configure.in
index 3cb0d199672..a1696db9219 100644
--- a/configure.in
+++ b/configure.in
@@ -1751,18 +1751,6 @@ 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.
-
-if test x"$HAVE_LONG_LONG_INT_64" = xyes ; then
-  AC_COMPILE_IFELSE([AC_LANG_SOURCE([
-#define INT64CONST(x)  x##LL
-long long int foo = INT64CONST(0x1234567890123456);
-])],
-	[AC_DEFINE(HAVE_LL_CONSTANTS, 1, [Define to 1 if constants of type 'long long int' should have the suffix LL.])],
-	[])
-fi
-
-
 # If we found "long int" is 64 bits, assume snprintf handles it.  If
 # we found we need to use "long long int", better check.  We cope with
 # snprintfs that use %lld, %qd, or %I64d as the format.  If none of these
diff --git a/src/include/c.h b/src/include/c.h
index f1f8b11877a..179e6248c7e 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -285,6 +285,8 @@ typedef long int int64;
 #ifndef HAVE_UINT64
 typedef unsigned long int uint64;
 #endif
+#define INT64CONST(x)  (x##L)
+#define UINT64CONST(x) (x##UL)
 #elif defined(HAVE_LONG_LONG_INT_64)
 /* We have working support for "long long int", use that */
 
@@ -294,20 +296,13 @@ typedef long long int int64;
 #ifndef HAVE_UINT64
 typedef unsigned long long int uint64;
 #endif
+#define INT64CONST(x)  (x##LL)
+#define UINT64CONST(x) (x##ULL)
 #else
 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
 #error must have a working 64-bit integer datatype
 #endif
 
-/* Decide if we need to decorate 64-bit constants */
-#ifdef HAVE_LL_CONSTANTS
-#define INT64CONST(x)  ((int64) x##LL)
-#define UINT64CONST(x) ((uint64) x##ULL)
-#else
-#define INT64CONST(x)  ((int64) x)
-#define UINT64CONST(x) ((uint64) x)
-#endif
-
 /* snprintf format strings to use for 64-bit integers */
 #define INT64_FORMAT "%" INT64_MODIFIER "d"
 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
@@ -335,14 +330,18 @@ typedef unsigned PG_INT128_TYPE uint128;
 #define PG_UINT16_MAX	(0xFFFF)
 #define PG_INT32_MIN	(-0x7FFFFFFF-1)
 #define PG_INT32_MAX	(0x7FFFFFFF)
-#define PG_UINT32_MAX	(0xFFFFFFFF)
+#define PG_UINT32_MAX	(0xFFFFFFFFU)
 #define PG_INT64_MIN	(-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
 #define PG_INT64_MAX	INT64CONST(0x7FFFFFFFFFFFFFFF)
 #define PG_UINT64_MAX	UINT64CONST(0xFFFFFFFFFFFFFFFF)
 
 /* Max value of size_t might also be missing if we don't have stdint.h */
 #ifndef SIZE_MAX
-#define SIZE_MAX ((size_t) -1)
+#if SIZEOF_SIZE_T == 8
+#define SIZE_MAX PG_UINT64_MAX
+#else
+#define SIZE_MAX PG_UINT32_MAX
+#endif
 #endif
 
 /* Select timestamp representation (float8 or int64) */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 7dbfa90bf49..a152371e61b 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -333,10 +333,6 @@
 /* Define to 1 if you have the `z' library (-lz). */
 #undef HAVE_LIBZ
 
-/* Define to 1 if constants of type 'long long int' should have the suffix LL.
-   */
-#undef HAVE_LL_CONSTANTS
-
 /* Define to 1 if the system has the type `locale_t'. */
 #undef HAVE_LOCALE_T
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 0e17ccbb405..65085d7d313 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -217,12 +217,6 @@
 /* Define to 1 if you have the `z' library (-lz). */
 /* #undef HAVE_LIBZ */
 
-/* Define to 1 if constants of type 'long long int' should have the suffix LL.
-   */
-#if (_MSC_VER > 1200)
-#define HAVE_LL_CONSTANTS 1
-#endif
-
 /* Define to 1 if the system has the type `locale_t'. */
 #define HAVE_LOCALE_T 1
 
@@ -231,7 +225,7 @@
 
 /* Define to 1 if `long long int' works and is 64 bits. */
 #if (_MSC_VER > 1200)
-#define HAVE_LONG_LONG_INT_64
+#define HAVE_LONG_LONG_INT_64 1
 #endif
 
 /* Define to 1 if you have the `mbstowcs_l' function. */