1 files changed, 4 insertions, 0 deletions
diff --git a/bignum.c b/bignum.c
index 451ed5a8e0..d316a60d82 100644
--- a/bignum.c
+++ b/bignum.c
@@ -304,6 +304,10 @@ rb_int2inum(SIGNED_VALUE n)
     return rb_int2big(n);
 }
 
+#if SIZEOF_LONG % SIZEOF_BDIGITS != 0
+# error unexpected SIZEOF_LONG : SIZEOF_BDIGITS ratio
+#endif
+
 void
 rb_big_pack(VALUE val, unsigned long *buf, long num_longs)
 {