diff --git a/configure.in b/configure.in
index ffe3f0364..481b29efc 100644
--- a/configure.in
+++ b/configure.in
@@ -61,6 +61,16 @@ AM_PROG_CC_STDC
 
 AC_C_CONST
 AC_C_INLINE
+AC_CHECK_SIZEOF(int)
+AC_CHECK_SIZEOF(long)
+AC_CACHE_CHECK([for long longs], scm_cv_long_longs,
+	       AC_TRY_COMPILE(,
+			      [long long a],
+			      scm_cv_long_longs=yes,
+			      scm_cv_long_longs=no))
+if test "$scm_cv_long_longs" = yes; then
+  AC_DEFINE(HAVE_LONG_LONGS)
+fi
 
 AC_HEADER_STDC
 AC_HEADER_DIRENT