diff --git a/gmp-h.in b/gmp-h.in
index a630d170..4378d3d5 100644
--- a/gmp-h.in
+++ b/gmp-h.in
@@ -53,14 +53,6 @@ along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
 #endif
 #undef __need_size_t
 
-#ifdef HAVE_STDINT_H
-#if defined (__cplusplus)
-#    include <cstdint>  /* for intmax_t/uintmax_t */
-#  else
-#    include <stdint.h> /* for intmax_t/uintmax_t */
-#  endif
-#endif
-
 /* Instantiated by configure. */
 #if ! defined (__GMP_WITHIN_CONFIGURE)
 @DEFN_LONG_LONG_LIMB@
@@ -1188,7 +1180,7 @@ __GMP_DECLSPEC void mpz_xor __GMP_PROTO ((mpz_ptr, mpz_srcptr, mpz_srcptr));
 
 /****** Integer (i.e. Z) routines for intmaax_t/uintmax_t types ******/
 
-#ifdef HAVE_STDINT_H
+#if defined( _STDINT_H ) || defined ( _STDINT_H_ ) || defined ( _STDINT )
 
 #define __GMP_BITS_PER_UINTMAX  (8*sizeof(uintmax_t))
 
diff --git a/mpz/get_sx.c b/mpz/get_sx.c
index e78e1d7e..e960cd94 100644
--- a/mpz/get_sx.c
+++ b/mpz/get_sx.c
@@ -21,7 +21,7 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
+#include <stdint.h>
 
 #include "mpir.h"
 #include "gmp-impl.h"
@@ -33,7 +33,7 @@ MA 02110-1301, USA. */
 intmax_t
 mpz_get_sx (mpz_srcptr z)
 {
-#if GMP_NUMB_BITS >= 8 * SIZEOF_UINTMAX_T
+#if NLIMBS == 1
     uintmax_t v = (intmax_t)(z->_mp_size ? z->_mp_d[0] : 0);
 #else
     uintmax_t v  = 0, n = MIN(NLIMBS, ABS(z->_mp_size));
diff --git a/mpz/get_ux.c b/mpz/get_ux.c
index 0eafab14..684e10b9 100644
--- a/mpz/get_ux.c
+++ b/mpz/get_ux.c
@@ -21,7 +21,7 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
+#include <stdint.h>
 
 #include "mpir.h"
 #include "gmp-impl.h"
@@ -33,7 +33,7 @@ MA 02110-1301, USA. */
 uintmax_t
 mpz_get_ux (mpz_srcptr z)
 {
-#if GMP_NUMB_BITS >= 8 * SIZEOF_UINTMAX_T
+#if NLIMBS == 1
     return (uintmax_t)(z->_mp_size ? z->_mp_d[0] : 0);
 #else
     uintmax_t v = 0, n = MIN(NLIMBS, ABS(z->_mp_size));
diff --git a/mpz/iset_sx.c b/mpz/iset_sx.c
index 69a39c98..1acd055f 100644
--- a/mpz/iset_sx.c
+++ b/mpz/iset_sx.c
@@ -20,7 +20,7 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
+#include <stdint.h>
 
 #include "mpir.h"
 #include "gmp-impl.h"
@@ -36,7 +36,7 @@ mpz_init_set_sx (mpz_ptr z, intmax_t v)
     z->_mp_d = (mp_ptr) (*__gmp_allocate_func) (MAX(1, NLIMBS) * BYTES_PER_MP_LIMB);
     z->_mp_alloc = MAX(1, NLIMBS);
 
-#if GMP_NUMB_BITS >= 8 * SIZEOF_UINTMAX_T
+#if NLIMBS == 1
     z->_mp_d[0] = (mp_limb_t)uv;
     z->_mp_size = v < 0 ? -NLIMBS : v ? NLIMBS : 0;
 #else
diff --git a/mpz/iset_ux.c b/mpz/iset_ux.c
index a79337c2..d1e8c278 100644
--- a/mpz/iset_ux.c
+++ b/mpz/iset_ux.c
@@ -20,7 +20,7 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
+#include <stdint.h>
 
 #include "mpir.h"
 #include "gmp-impl.h"
@@ -36,7 +36,7 @@ mpz_init_set_ux (mpz_ptr z, uintmax_t v)
     z->_mp_d = (mp_ptr) (*__gmp_allocate_func) (MAX(1, NLIMBS) * BYTES_PER_MP_LIMB);
     z->_mp_alloc = MAX(1, NLIMBS);
 
-#if GMP_NUMB_BITS >= 8 * SIZEOF_UINTMAX_T
+#if NLIMBS == 1
     z->_mp_d[0] = (mp_limb_t)v;
     z->_mp_size = (v ? NLIMBS : 0);
 #else
diff --git a/mpz/set_sx.c b/mpz/set_sx.c
index fead8d84..be1c525d 100644
--- a/mpz/set_sx.c
+++ b/mpz/set_sx.c
@@ -20,7 +20,7 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
+#include <stdint.h>
 
 #include "mpir.h"
 #include "gmp-impl.h"
@@ -33,7 +33,7 @@ void
 mpz_set_sx (mpz_ptr z, intmax_t v)
 {   uintmax_t i, uv = (v < 0 ? -v : v);
 
-#if GMP_NUMB_BITS >= 8 * SIZEOF_UINTMAX_T
+#if NLIMBS == 1
     z->_mp_d[0] = (mp_limb_t)uv;
     z->_mp_size = v < 0 ? -NLIMBS : v ? NLIMBS : 0;
 #else
diff --git a/mpz/set_ux.c b/mpz/set_ux.c
index 0bcb271c..0555530e 100644
--- a/mpz/set_ux.c
+++ b/mpz/set_ux.c
@@ -20,7 +20,7 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
+#include <stdint.h>
 
 #include "mpir.h"
 #include "gmp-impl.h"
@@ -33,7 +33,7 @@ void
 mpz_set_ux (mpz_ptr z, uintmax_t v)
 {   uintmax_t i, uv;
 
-#if GMP_NUMB_BITS >= 8 * SIZEOF_UINTMAX_T
+#if NLIMBS == 1
     z->_mp_d[0] = (mp_limb_t)v;
     z->_mp_size = (v ? NLIMBS : 0);
 #else
diff --git a/tests/mpz/t-get_sx.c b/tests/mpz/t-get_sx.c
index a2f9b2c7..3ffe0173 100644
--- a/tests/mpz/t-get_sx.c
+++ b/tests/mpz/t-get_sx.c
@@ -21,10 +21,9 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
-
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include "mpir.h"
 #include "gmp-impl.h"
 #include "tests.h"
diff --git a/tests/mpz/t-set_sx.c b/tests/mpz/t-set_sx.c
index 6955c817..3e0fc168 100644
--- a/tests/mpz/t-set_sx.c
+++ b/tests/mpz/t-set_sx.c
@@ -20,10 +20,9 @@ along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 MA 02110-1301, USA. */
 
-#define HAVE_STDINT_H
-
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include "mpir.h"
 #include "gmp-impl.h"
 #include "tests.h"