diff --git a/configure.in b/configure.in
index a28d07df2..32c5481e0 100644
--- a/configure.in
+++ b/configure.in
@@ -165,10 +165,12 @@ AC_C_BIGENDIAN
 AC_CHECK_SIZEOF(int)
 AC_CHECK_SIZEOF(long)
 
-dnl by the pre C9X ANSI C standards, size_t & ptrdiff_t have to be
-dnl representable by a standard integral type.  since the largest 
-dnl integer type in the pre-C9X ANSI C standards is long...
-AC_CHECK_TYPE(ptrdiff_t, long)
+dnl Check for integral types that can represent the range of pointers.
+dnl If these types don't exist on this platform, they are replaced by
+dnl "unsigned long" and "long", respectively.
+
+AC_CHECK_HEADERS(stdint.h)
+AC_CHECK_TYPES([uintptr_t, ptrdiff_t])
 
 AC_CACHE_CHECK([for long longs], scm_cv_long_longs,
 	       AC_TRY_COMPILE(,