diff --git a/opt/bignum.c b/opt/bignum.c
index 82c96bdc..e69d6582 100644
--- a/opt/bignum.c
+++ b/opt/bignum.c
@@ -1521,7 +1521,8 @@ sexp sexp_compare (sexp ctx, sexp a, sexp b) {
       break;
 #if SEXP_USE_RATIOS
     case SEXP_NUM_FLO_RAT:
-      r = sexp_make_fixnum((sexp_sint_t)(sexp_flonum_value(a) - sexp_ratio_to_double(b)));
+      f = sexp_flonum_value(a) - sexp_ratio_to_double(b);
+      r = sexp_make_fixnum(f > 0.0 ? 1 : f == 0.0 ? 0 : -1);
       break;
     case SEXP_NUM_FIX_RAT:
     case SEXP_NUM_BIG_RAT:
diff --git a/tests/numeric-tests.scm b/tests/numeric-tests.scm
index f221d64e..5f720e78 100644
--- a/tests/numeric-tests.scm
+++ b/tests/numeric-tests.scm
@@ -119,4 +119,14 @@
         (-18446744078004518913 -18446744069414584321 79228162514264337597838917632 4294967296 -1))
     (sign-combinations (+ 1 (expt 2 64)) (expt 2 32)))
 
+(cond-expand
+ (ratios
+  (test #t (< 1/2 1.0))
+  (test #t (< 1.0 3/2))
+  (test #t (< 1/2 1.5))
+  (test #t (< 1/2 2.0))
+  (test 1.0 (max 1/2 1.0)))
+ (else
+  #f))
+
 (test-end)