diff --git a/include/chibi/sexp.h b/include/chibi/sexp.h
index 1a81cdc4..f3d9f6b5 100755
--- a/include/chibi/sexp.h
+++ b/include/chibi/sexp.h
@@ -802,6 +802,9 @@ SEXP_API sexp sexp_make_unsigned_integer(sexp ctx, sexp_luint_t x);
 #define sexp_shift_epoch(x) ((x)-SEXP_EPOCH_OFFSET)
 #define sexp_unshift_epoch(x) ((x)+SEXP_EPOCH_OFFSET)
 
+#define sexp_infp(x) (sexp_flonump(x) && isinf(sexp_flonum_value(x)))
+#define sexp_nanp(x) (sexp_flonump(x) && isnan(sexp_flonum_value(x)))
+
 /*************************** field accessors **************************/
 
 #if SEXP_USE_SAFE_ACCESSORS
diff --git a/opt/bignum.c b/opt/bignum.c
index aa73e6a8..def182e5 100644
--- a/opt/bignum.c
+++ b/opt/bignum.c
@@ -1479,7 +1479,7 @@ sexp sexp_remainder (sexp ctx, sexp a, sexp b) {
 sexp sexp_compare (sexp ctx, sexp a, sexp b) {
   int at=sexp_number_type(a), bt=sexp_number_type(b);
   sexp r=SEXP_VOID;
-  double f;
+  double f, g;
   sexp_gc_var1(tmp);
   sexp_gc_preserve1(ctx, tmp);
   if (at > bt) {
@@ -1502,27 +1502,31 @@ sexp sexp_compare (sexp ctx, sexp a, sexp b) {
       r = sexp_make_fixnum(sexp_unbox_fixnum(a) - sexp_unbox_fixnum(b));
       break;
     case SEXP_NUM_FIX_FLO:
-      f = sexp_fixnum_to_double(a) - sexp_flonum_value(b);
-      r = sexp_make_fixnum(f > 0.0 ? 1 : f == 0.0 ? 0 : -1);
+      f = sexp_fixnum_to_double(a);
+      g = sexp_flonum_value(b);
+      r = sexp_make_fixnum(f < g ? -1 : f == g ? 0 : 1);
       break;
     case SEXP_NUM_FIX_BIG:
       r = sexp_make_fixnum(sexp_bignum_sign(b) < 0 ? 1 : -1);
       break;
     case SEXP_NUM_FLO_FLO:
-      f = sexp_flonum_value(a) - sexp_flonum_value(b);
-      r = sexp_make_fixnum(f > 0.0 ? 1 : f == 0.0 ? 0 : -1);
+      f = sexp_flonum_value(a);
+      g = sexp_flonum_value(b);
+      r = sexp_make_fixnum(f < g ? -1 : f == g ? 0 : 1);
       break;
     case SEXP_NUM_FLO_BIG:
-      f = sexp_flonum_value(a) - sexp_bignum_to_double(b);
-      r = sexp_make_fixnum(f > 0.0 ? 1 : f == 0.0 ? 0 : -1);
+      f = sexp_flonum_value(a);
+      g = sexp_bignum_to_double(b);
+      r = sexp_make_fixnum(f < g ? -1 : f == g ? 0 : 1);
       break;
     case SEXP_NUM_BIG_BIG:
       r = sexp_make_fixnum(sexp_bignum_compare(a, b));
       break;
 #if SEXP_USE_RATIOS
     case SEXP_NUM_FLO_RAT:
-      f = sexp_flonum_value(a) - sexp_ratio_to_double(b);
-      r = sexp_make_fixnum(f > 0.0 ? 1 : f == 0.0 ? 0 : -1);
+      f = sexp_flonum_value(a);
+      g = sexp_ratio_to_double(b);
+      r = sexp_make_fixnum(f < g ? -1 : f == g ? 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 5f720e78..dc087edd 100644
--- a/tests/numeric-tests.scm
+++ b/tests/numeric-tests.scm
@@ -119,6 +119,30 @@
         (-18446744078004518913 -18446744069414584321 79228162514264337597838917632 4294967296 -1))
     (sign-combinations (+ 1 (expt 2 64)) (expt 2 32)))
 
+(test #f (< +nan.0 +nan.0))
+(test #f (<= +nan.0 +nan.0))
+(test #f (= +nan.0 +nan.0))
+(test #f (>= +nan.0 +nan.0))
+(test #f (> +nan.0 +nan.0))
+
+(test #f (< +inf.0 +inf.0))
+(test #t (<= +inf.0 +inf.0))
+(test #t (= +inf.0 +inf.0))
+(test #t (>= +inf.0 +inf.0))
+(test #f (> +inf.0 +inf.0))
+
+(test #f (< -inf.0 -inf.0))
+(test #t (<= -inf.0 -inf.0))
+(test #t (= -inf.0 -inf.0))
+(test #t (>= -inf.0 -inf.0))
+(test #f (> -inf.0 -inf.0))
+
+(test #t (< -inf.0 +inf.0))
+(test #t (<= -inf.0 +inf.0))
+(test #f (= -inf.0 +inf.0))
+(test #f (>= -inf.0 +inf.0))
+(test #f (> -inf.0 +inf.0))
+
 (cond-expand
  (ratios
   (test #t (< 1/2 1.0))