diff --git a/lib/kitchen/driver/openstack.rb b/lib/kitchen/driver/openstack.rb
index b0b9552c..b58c9e32 100644
--- a/lib/kitchen/driver/openstack.rb
+++ b/lib/kitchen/driver/openstack.rb
@@ -199,7 +199,7 @@ def generate_name(base)
           Socket.gethostname,
           Array.new(8) { rand(36).to_s(36) }.join
         ]
-        until pieces.join(sep).length <= 64 do
+        until pieces.join(sep).length <= 63 do
           if pieces[2].length > 24
             pieces[2] = pieces[2][0..-2]
           elsif pieces[1].length > 16
diff --git a/spec/kitchen/driver/openstack_spec.rb b/spec/kitchen/driver/openstack_spec.rb
index 9817dfcb..a72be36f 100644
--- a/spec/kitchen/driver/openstack_spec.rb
+++ b/spec/kitchen/driver/openstack_spec.rb
@@ -619,8 +619,8 @@
         Socket.stub(:gethostname).and_return('ab.c' * 20)
       end
 
-      it 'limits the generated name to 64-characters' do
-        expect(driver.send(:generate_name, 'long').length).to eq(64)
+      it 'limits the generated name to 63-characters' do
+        expect(driver.send(:generate_name, 'long').length).to eq(63)
       end
     end
   end