diff --git a/app/models/ptr.rb b/app/models/ptr.rb
index a61dda3..5817b89 100644
--- a/app/models/ptr.rb
+++ b/app/models/ptr.rb
@@ -1,6 +1,15 @@
 class PTR < Record
   validates :content, presence: true, hostname: true
+  validate :no_trailing_dot
 
   before_validation :remove_terminating_dot
+
+  def no_trailing_dot
+    # Do not allow PTR record names that end with a dot
+    return if !short.end_with?(".")
+
+    errors.add(:name, "PTR record name should not end with a dot")
+  end
+
 end
 
diff --git a/test/models/ptr_test.rb b/test/models/ptr_test.rb
index 82ddf84..26cf87e 100644
--- a/test/models/ptr_test.rb
+++ b/test/models/ptr_test.rb
@@ -1,50 +1,62 @@
 require 'test_helper'
 
 class PTRTest < ActiveSupport::TestCase
   class V4PTRTest < ActiveSupport::TestCase
     setup do
       @record = build(:v4_ptr)
     end
 
     test 'save' do
       @record.save
 
       assert_empty @record.errors
     end
 
     test 'guess record' do
       @record.name = @record.domain.name.split(".")[0..-3].reverse.join(".") + ".1"
       assert @record.save
 
       assert_equal @record.name, "1." + @record.domain.name
     end
 
     test 'chop terminating dot' do
       @record.content = 'with-dot.example.com.'
       @record.save!
       @record.reload
 
       assert_equal 'with-dot.example.com', @record.content
     end
+
+    test "name invalid" do
+      rec = build(:v4_ptr, name: "195.")
+      rec.valid?
+      assert_not_empty rec.errors[:name], "name '195.' should be invalid"
+    end
+
+    test "name valid" do
+      rec = build(:v4_ptr, name: "195")
+      rec.valid?
+      assert_empty rec.errors[:name], "name '195' should be valid"
+    end
   end
 
   class V6PTRTest < ActiveSupport::TestCase
     setup do
       @record = build(:v6_ptr)
     end
 
     test 'save' do
       @record.save
       assert_empty @record.errors
     end
 
     test 'guess record' do
       @record.name = '2001:db' + @record.domain.name.split(".")[0] + '::2'
       assert @record.save
 
       assert_equal '2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.' + @record.domain.name,
                    @record.name
     end
   end
 
 end
diff --git a/test/models/record_test.rb b/test/models/record_test.rb
index 1559023..e31dc90 100644
--- a/test/models/record_test.rb
+++ b/test/models/record_test.rb
@@ -1,19 +1,20 @@
 require 'test_helper'
 
 class RecordTest < ActiveSupport::TestCase
   ['text', -1, 0, 2_147_483_647 + 1].each { |ttl|
     test "ttl invalid #{ttl}" do
       rec = build(:a, ttl: ttl)
       rec.valid?
       assert_not_empty rec.errors[:ttl], "ttl #{ttl} should be invalid!"
     end
   }
 
   ['', 1, 2_147_483_647].each { |ttl|
     test "ttl valid #{ttl}" do
       rec = build(:a, ttl: ttl)
       rec.valid?
       assert_empty rec.errors[:ttl], "ttl #{ttl} should be valid!"
     end
   }
+
 end