diff --git a/ChangeLog b/ChangeLog
index 5273505841..fc543a662f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Apr  3 10:51:10 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* random.c (random_rand): raise ArgumentError on nil, as the
+	  documentation implies.  [ruby-core:29075]
+
+	* random.c (rb_f_rand): mentioned the case of when max is nil.
+
 Sat Apr  3 06:56:11 2010  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
 
 	* array.c (rb_ary_product): Accept a block [ruby-core:29045]
diff --git a/random.c b/random.c
index 9e35861fad..6efefe6232 100644
--- a/random.c
+++ b/random.c
@@ -989,7 +989,6 @@ random_rand(int argc, VALUE *argv, VALUE obj)
     int excl = 0;
 
     if (argc == 0) {
-      zero_arg:
 	return rb_float_new(genrand_real(&rnd->mt));
     }
     else if (argc != 1) {
@@ -997,7 +996,7 @@ random_rand(int argc, VALUE *argv, VALUE obj)
     }
     vmax = argv[0];
     if (NIL_P(vmax)) {
-	goto zero_arg;
+	v = Qnil;
     }
     else if (TYPE(vmax) != T_FLOAT && (v = rb_check_to_integer(vmax, "to_int"), !NIL_P(v))) {
 	v = rand_int(&rnd->mt, vmax = v, 1);
@@ -1098,7 +1097,7 @@ random_equal(VALUE self, VALUE other)
  *     rand(max=0)    => number
  *
  *  Converts <i>max</i> to an integer using max1 =
- *  max<code>.to_i.abs</code>. If the result is zero, returns a
+ *  max<code>.to_i.abs</code>. If _max_ is +nil+ the result is zero, returns a
  *  pseudorandom floating point number greater than or equal to 0.0 and
  *  less than 1.0. Otherwise, returns a pseudorandom integer greater
  *  than or equal to zero and less than max1. <code>Kernel::srand</code>
diff --git a/test/ruby/test_rand.rb b/test/ruby/test_rand.rb
index 97ac8147bd..157f542dea 100644
--- a/test/ruby/test_rand.rb
+++ b/test/ruby/test_rand.rb
@@ -207,6 +207,7 @@ class TestRand < Test::Unit::TestCase
     assert_raise(ArgumentError, '[ruby-dev:39166]') { r.rand(0..-1) }
     assert_raise(ArgumentError, '[ruby-dev:39166]') { r.rand(0.0...0.0) }
     assert_raise(ArgumentError, '[ruby-dev:39166]') { r.rand(0.0...-0.1) }
+    assert_raise(ArgumentError, bug3027 = '[ruby-core:29075]') { r.rand(nil) }
   end
 
   def test_random_seed