diff --git a/src/numeric.c b/src/numeric.c
index 9902b0b94..cdf8c8afb 100644
--- a/src/numeric.c
+++ b/src/numeric.c
@@ -291,7 +291,7 @@ value_int64(mrb_state *mrb, mrb_value x)
 static mrb_value
 int64_value(mrb_state *mrb, int64_t v)
 {
-  if (MRB_INT_MIN <= v && v <= MRB_INT_MAX) {
+  if (FIXABLE(v)) {
     return mrb_fixnum_value((mrb_int)v);
   }
   return mrb_float_value(mrb, (mrb_float)v);