diff --git a/lib/vagrant-libvirt/config.rb b/lib/vagrant-libvirt/config.rb
index c96051b..c8e93ba 100644
--- a/lib/vagrant-libvirt/config.rb
+++ b/lib/vagrant-libvirt/config.rb
@@ -647,28 +647,26 @@ module VagrantPlugins
           uri << '+ssh://'
           uri << @username + '@' if @username
 
-          uri << if @host
-                   @host
-                 else
-                   'localhost'
-                 end
+          uri << ( @host ? @host : 'localhost' )
         else
           uri << '://'
           uri << @host if @host
         end
 
         uri << virt_path
-        uri << '?no_verify=1'
+
+        params = {'no_verify' => '1'}
 
         if @id_ssh_key_file
           # set ssh key for access to Libvirt host
-          uri << "\&keyfile="
           # if no slash, prepend $HOME/.ssh/
-          @id_ssh_key_file.prepend("#{`echo ${HOME}`.chomp}/.ssh/") if @id_ssh_key_file !~ /\A\//
-          uri << @id_ssh_key_file
+          @id_ssh_key_file.prepend("#{ENV['HOME']}/.ssh/") if @id_ssh_key_file !~ /\A\//
+          params['keyfile'] = @id_ssh_key_file
         end
         # set path to Libvirt socket
-        uri << "\&socket=" + @socket if @socket
+        params['socket'] = @socket if @socket
+
+        uri << "?" + params.map{|pair| pair.join('=')}.join('&')
         uri
       end
 
diff --git a/spec/unit/config_spec.rb b/spec/unit/config_spec.rb
index 72101c9..1708a72 100644
--- a/spec/unit/config_spec.rb
+++ b/spec/unit/config_spec.rb
@@ -6,6 +6,129 @@ require 'vagrant-libvirt/config'
 describe VagrantPlugins::ProviderLibvirt::Config do
   include_context 'unit'
 
+  let(:fake_env) { Hash.new }
+
+  describe '#finalize!' do
+    it 'is valid with defaults' do
+      subject.finalize!
+    end
+
+    context '@uri' do
+      before(:example) do
+        stub_const("ENV", fake_env)
+      end
+
+      context 'when @driver is defined' do
+        defaults = {'id_ssh_key_file' => nil}
+        [
+          [
+            {'driver' => 'kvm'},
+            'qemu:///system?no_verify=1',
+            false,
+          ],
+          [
+            {'driver' => 'qemu'},
+            'qemu:///system?no_verify=1',
+            false,
+          ],
+          [
+            {'driver' => 'qemu', 'qemu_use_session' => true},
+            'qemu:///session?no_verify=1',
+            true,
+          ],
+          [
+            {'driver' => 'openvz'},
+            'openvz:///system?no_verify=1',
+            false,
+          ],
+          [
+            {'driver' => 'vbox'},
+            'vbox:///session?no_verify=1',
+            false,
+          ],
+        ].each do |inputs, output_uri, output_session|
+          it "should detect #{inputs}" do
+            inputs.merge(defaults).each do |k, v|
+              subject.instance_variable_set("@#{k}", v)
+            end
+
+            subject.finalize!
+            expect(subject.uri).to eq(output_uri)
+            expect(subject.qemu_use_session).to eq(output_session)
+          end
+        end
+
+        it "should raise exception for unrecognized" do
+          subject.driver = "bad-driver"
+
+          expect { subject.finalize! }.to raise_error("Require specify driver bad-driver")
+        end
+      end
+
+      context 'when @connect_via_ssh defined' do
+        defaults = {'driver' => 'qemu', 'id_ssh_key_file' => nil}
+        [
+          [
+            {'connect_via_ssh' => true},
+            'qemu+ssh://localhost/system?no_verify=1',
+          ],
+          [
+            {'connect_via_ssh' => true, 'username' => 'my_user'},
+            'qemu+ssh://my_user@localhost/system?no_verify=1',
+          ],
+          [
+            {'connect_via_ssh' => true, 'host' => 'remote_server'},
+            'qemu+ssh://remote_server/system?no_verify=1',
+          ],
+        ].each do |inputs, output_uri|
+          it "should detect #{inputs}" do
+            inputs.merge(defaults).each do |k, v|
+              subject.instance_variable_set("@#{k}", v)
+            end
+
+            subject.finalize!
+            expect(subject.uri).to eq(output_uri)
+          end
+        end
+      end
+
+      context 'when @id_ssh_key_file defined' do
+        defaults = {'driver' => 'qemu'}
+        [
+          [
+            {},
+            'qemu:///system?no_verify=1&keyfile=/home/user/.ssh/id_rsa',
+          ],
+          [
+            {'id_ssh_key_file' => '/path/to/keyfile'},
+            'qemu:///system?no_verify=1&keyfile=/path/to/keyfile',
+          ],
+        ].each do |inputs, output_uri|
+          it "should detect #{inputs}" do
+            inputs.merge(defaults).each do |k, v|
+              subject.instance_variable_set("@#{k}", v)
+            end
+
+            fake_env['HOME'] = '/home/user'
+
+            subject.finalize!
+            expect(subject.uri).to eq(output_uri)
+          end
+        end
+      end
+
+      context 'when @socket defined' do
+        it "should detect @socket set" do
+          subject.socket = '/var/run/libvirt/libvirt-sock'
+          subject.id_ssh_key_file = false
+
+          subject.finalize!
+          expect(subject.uri).to eq('qemu:///system?no_verify=1&socket=/var/run/libvirt/libvirt-sock')
+        end
+      end
+    end
+  end
+
   def assert_invalid
     errors = subject.validate(machine)
     raise "No errors: #{errors.inspect}" if errors.values.all?(&:empty?)