diff --git a/lib/anemone/core.rb b/lib/anemone/core.rb
index d1629a49..33c844ec 100644
--- a/lib/anemone/core.rb
+++ b/lib/anemone/core.rb
@@ -55,7 +55,9 @@ class Core
       # proxy server port number
       :proxy_port => false,
       # HTTP read timeout in seconds
-      :read_timeout => nil
+      :read_timeout => nil,
+      # Crawl subdomains?
+      :crawl_subdomains => false,
     }
 
     # Create setter methods for all options to be called from the crawl block
@@ -72,6 +74,7 @@ class Core
     def initialize(urls, opts = {})
       @urls = [urls].flatten.map{ |url| url.is_a?(URI) ? url : URI(url) }
       @urls.each{ |url| url.path = '/' if url.path.empty? }
+      @valid_domains = @urls.map{|u| [u.host,u.host.gsub(/^www\./,'.')]}.flatten.compact.uniq
 
       @tentacles = []
       @on_every_page_blocks = []
@@ -256,7 +259,16 @@ def visit_link?(link, from_page = nil)
       !skip_link?(link) &&
       !skip_query_string?(link) &&
       allowed(link) &&
-      !too_deep?(from_page)
+      !too_deep?(from_page) &&
+      (in_allowed_domain?(link) or in_allowed_subdomain?(link))
+    end
+
+    def in_allowed_domain?(link)
+      @valid_domains.index(link.host)
+    end
+
+    def in_allowed_subdomain?(link)
+      opts[:crawl_subdomains] and @valid_domains.find{|domain| link.host.end_with?(domain)}
     end
 
     #
diff --git a/lib/anemone/page.rb b/lib/anemone/page.rb
index b157ad63..3c914722 100644
--- a/lib/anemone/page.rb
+++ b/lib/anemone/page.rb
@@ -63,7 +63,7 @@ def links
         u = a['href']
         next if u.nil? or u.empty?
         abs = to_absolute(u) rescue next
-        @links << abs if in_domain?(abs)
+        @links << abs
       end
       @links.uniq!
       @links
diff --git a/spec/core_spec.rb b/spec/core_spec.rb
index 775c79f1..cc84ff84 100644
--- a/spec/core_spec.rb
+++ b/spec/core_spec.rb
@@ -42,6 +42,18 @@ module Anemone
         core.pages.keys.should_not include('http://www.other.com/')
       end
 
+      it "should follow links to subdomains" do
+        pages = []
+        pages << FakePage.new('0', :links => ['1'], :hrefs => [ 'http://www.other.com/', 'http://subdomain.example.com/'] )
+        pages << FakePage.new('1')
+
+        core = Anemone.crawl(pages[0].url, @opts.merge({:crawl_subdomains => true}))
+
+        core.should have(3).pages
+        core.pages.keys.should_not include('http://www.other.com/')
+        core.pages.keys.should include('http://subdomain.example.com/')
+      end
+
       it "should follow http redirects" do
         pages = []
         pages << FakePage.new('0', :links => ['1'])