1 files changed, 12 insertions, 7 deletions

diff --git a/range.c b/range.c
index e94ee13599..f460dcbb58 100644
--- a/range.c
+++ b/range.c
@@ -307,23 +307,28 @@ range_step(argc, argv, range)
     VALUE *argv;
     VALUE range;
 {
-    VALUE b, e, step;
+    VALUE b, e, step, tmp;
     long unit;
 
     RETURN_ENUMERATOR(range, argc, argv);
 
     b = rb_ivar_get(range, id_beg);
     e = rb_ivar_get(range, id_end);
-    if (rb_scan_args(argc, argv, "01", &step) == 0) {
+    if (argc == 0) {
 	step = INT2FIX(1);
 	unit = 1;
     }
-    else if (FIXNUM_P(step)) {
-	unit = NUM2LONG(step);
-    }
     else {
-	VALUE tmp = rb_to_int(step);
-	unit = rb_cmpint(tmp, step, INT2FIX(0));
+	rb_scan_args(argc, argv, "01", &step);
+	tmp = rb_check_to_integer(step, "to_int");
+	if (!NIL_P(tmp)) {
+	    step = tmp;
+	    unit = NUM2LONG(step);
+	}
+	else {
+	    tmp = rb_funcall(rb_funcall(b, '+', 1, step), '-', 1, b);
+	    unit = rb_cmpint(tmp, step, INT2FIX(0));
+	}
     }
     if (unit < 0) {
 	rb_raise(rb_eArgError, "step can't be negative");