diff --git a/Gemfile.lock b/Gemfile.lock
index 835df6a..fc5f4c2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    serrano (0.2.2)
+    serrano (0.2.2.1)
       faraday (~> 0.9.2)
       faraday_middleware (~> 0.10.0)
       multi_json (~> 1.12, >= 1.12.1)
diff --git a/lib/serrano.rb b/lib/serrano.rb
index ec4e11c..e49d491 100644
--- a/lib/serrano.rb
+++ b/lib/serrano.rb
@@ -14,6 +14,7 @@
 #   @param limit [Fixnum] Number of results to return. Not relavant when searching with specific dois. Default: 20. Max: 1000
 #   @param sample [Fixnum] Number of random results to return. when you use the sample parameter,
 #       the limit and offset parameters are ignored. This parameter only used when works requested.
+#       Max: 100.
 #   @param sort [String] Field to sort on, one of score, relevance,
 #       updated (date of most recent change to metadata - currently the same as deposited),
 #       deposited (time of most recent deposit), indexed (time of most recent index), or
@@ -393,7 +394,7 @@ def self.registration_agency(ids:, options: nil, verbose: false)
   # Get a random set of DOI's
   #
   # @!macro serrano_options
-  # @param sample [Fixnum] Number of random DOIs to return
+  # @param sample [Fixnum] Number of random DOIs to return. Max: 100. Default: 10
   # @param verbose [Boolean] Print request headers to stdout. Default: false
   # @return [Array] A list of strings, each a DOI
   # @note This method uses {Serrano.works} internally, but doesn't allow you to pass on
diff --git a/lib/serrano/version.rb b/lib/serrano/version.rb
index 9ad8bf2..f187a46 100644
--- a/lib/serrano/version.rb
+++ b/lib/serrano/version.rb
@@ -1,3 +1,3 @@
 module Serrano
-  VERSION = "0.2.2"
+  VERSION = "0.2.2.1"
 end
diff --git a/test/test-random_dois.rb b/test/test-random_dois.rb
new file mode 100644
index 0000000..5249416
--- /dev/null
+++ b/test/test-random_dois.rb
@@ -0,0 +1,33 @@
+require 'simplecov'
+SimpleCov.start
+if ENV['CI']=='true'
+  require 'codecov'
+  SimpleCov.formatter = SimpleCov::Formatter::Codecov
+end
+
+require "serrano"
+require "serrano/error"
+require 'fileutils'
+require "test/unit"
+require "json"
+
+class TestRandomDois < Test::Unit::TestCase
+
+  def test_random_dois
+    res = Serrano.random_dois()
+    assert_equal(10, res.length)
+    assert_equal(Array, res.class)
+    assert_equal(String, res[0].class)
+  end
+
+  def test_random_dois_limit
+    res = Serrano.random_dois(sample: 3)
+    assert_equal(3, res.length)
+  end
+
+  def test_random_dois_errors
+    assert_raise Serrano::BadRequest do
+      puts Serrano.random_dois(sample: 101)
+    end
+  end
+end