diff --git a/lib/pretty_text.rb b/lib/pretty_text.rb
index 9652dc2b545..2f6417f8949 100644
--- a/lib/pretty_text.rb
+++ b/lib/pretty_text.rb
@@ -242,8 +242,9 @@ module PrettyText
         site_uri ||= URI(Discourse.base_url)
 
         if !uri.host.present? ||
-           uri.host.ends_with?(site_uri.host) ||
-           whitelist.any?{|u| uri.host.ends_with?(u)}
+           uri.host == site_uri.host ||
+           uri.host.ends_with?("." << site_uri.host) ||
+           whitelist.any?{|u| uri.host == u || uri.host.ends_with?("." << u)}
           # we are good no need for nofollow
         else
           l["rel"] = "nofollow"
diff --git a/spec/components/pretty_text_spec.rb b/spec/components/pretty_text_spec.rb
index 4f6a0f6f45a..66a64a404b3 100644
--- a/spec/components/pretty_text_spec.rb
+++ b/spec/components/pretty_text_spec.rb
@@ -69,10 +69,18 @@ describe PrettyText do
       expect(PrettyText.cook("<a href='#{Discourse.base_url.sub('http://', 'http://bla.')}/test.html'>cnn</a>") !~ /nofollow/).to eq(true)
     end
 
+    it "should inject nofollow in all non subdomain links" do
+      expect(PrettyText.cook("<a href='#{Discourse.base_url.sub('http://', 'http://bla')}/test.html'>cnn</a>")).to match(/nofollow/)
+    end
+
     it "should not inject nofollow for foo.com" do
       expect(PrettyText.cook("<a href='http://foo.com/test.html'>cnn</a>") !~ /nofollow/).to eq(true)
     end
 
+    it "should inject nofollow for afoo.com" do
+      expect(PrettyText.cook("<a href='http://afoo.com/test.html'>cnn</a>")).to match(/nofollow/)
+    end
+
     it "should not inject nofollow for bar.foo.com" do
       expect(PrettyText.cook("<a href='http://bar.foo.com/test.html'>cnn</a>") !~ /nofollow/).to eq(true)
     end