diff --git a/rational.c b/rational.c
index ebc6979a97..3917541c13 100644
--- a/rational.c
+++ b/rational.c
@@ -715,6 +715,7 @@ f_addsub(VALUE self, VALUE anum, VALUE aden, VALUE bnum, VALUE bden, int k)
     return f_rational_new_no_reduce2(CLASS_OF(self), num, den);
 }
 
+static VALUE nurat_to_f(VALUE self);
 /*
  * call-seq:
  *    rat + numeric  ->  numeric
@@ -740,7 +741,7 @@ rb_rational_plus(VALUE self, VALUE other)
 	}
     }
     else if (RB_TYPE_P(other, T_FLOAT)) {
-	return f_add(f_to_f(self), other);
+	return DBL2NUM(RFLOAT_VALUE(nurat_to_f(self)) + RFLOAT_VALUE(other));
     }
     else if (RB_TYPE_P(other, T_RATIONAL)) {
 	{