diff --git a/bignum.c b/bignum.c
index 526fa536..f61a7b6a 100644
--- a/bignum.c
+++ b/bignum.c
@@ -146,7 +146,8 @@ sexp_sint_t sexp_bignum_compare_abs (sexp a, sexp b) {
 sexp_sint_t sexp_bignum_compare (sexp a, sexp b) {
   if (sexp_bignum_sign(a) != sexp_bignum_sign(b))
     return sexp_bignum_sign(a);
-  return sexp_bignum_compare_abs(a, b);
+  sexp_sint_t cmp = sexp_bignum_compare_abs(a, b);
+  return sexp_bignum_sign(a) < 0 ? -cmp : cmp;
 }
 
 sexp sexp_bignum_normalize (sexp a) {
diff --git a/lib/chibi/numeric-test.sld b/lib/chibi/numeric-test.sld
index 9d476ebc..c329be29 100644
--- a/lib/chibi/numeric-test.sld
+++ b/lib/chibi/numeric-test.sld
@@ -272,6 +272,11 @@
           (+ 115792089237316195423570985008687907853099843482180094807725896704197245534208
              115792089237316195423570985008687907853099843482180094807725896704197245534208))
 
+      (let ((smallest-s64 -9223372036854775808)
+            (small-bignum -100000000000000000000000000))
+        (test-assert (> smallest-s64 small-bignum))
+        (test-assert (< small-bignum smallest-s64)))
+
       (test #f (< +nan.0 +nan.0))
       (test #f (<= +nan.0 +nan.0))
       (test #f (= +nan.0 +nan.0))