diff --git a/manifests/controller.pp b/manifests/controller.pp
index 6109028..2a013eb 100644
--- a/manifests/controller.pp
+++ b/manifests/controller.pp
@@ -147,7 +147,7 @@ class ovn::controller(
   String $ovn_remote,
   Stdlib::IP::Address $ovn_encap_ip,
   String $package_ensure                                            = 'present',
-  Variant[String[1], Array[String[1]]] $ovn_encap_type              = 'geneve',
+  Variant[Ovn::EncapType, Array[Ovn::EncapType]] $ovn_encap_type    = 'geneve',
   Optional[Variant[String, Integer]] $ovn_encap_tos                 = undef,
   Ovn::BridgeMappings $ovn_bridge_mappings                          = [],
   Array[String[1]] $bridge_interface_mappings                       = [],
diff --git a/spec/type_aliases/encaptype_spec.rb b/spec/type_aliases/encaptype_spec.rb
new file mode 100644
index 0000000..f867ffb
--- /dev/null
+++ b/spec/type_aliases/encaptype_spec.rb
@@ -0,0 +1,35 @@
+require 'spec_helper'
+
+describe 'Ovn::EncapType' do
+  describe 'valid types' do
+    context 'with valid types' do
+      [
+        'geneve',
+        'vxlan'
+      ].each do |value|
+        describe value.inspect do
+          it { is_expected.to allow_value(value) }
+        end
+      end
+    end
+  end
+
+  describe 'invalid types' do
+    context 'with garbage inputs' do
+      [
+        '',
+        'vlan',
+        true,
+        false,
+        1,
+        ['vxlan'],
+        {'' => 'vxlan'},
+        {'vxlan' => ''}
+      ].each do |value|
+        describe value.inspect do
+          it { is_expected.not_to allow_value(value) }
+        end
+      end
+    end
+  end
+end
diff --git a/types/encaptype.pp b/types/encaptype.pp
new file mode 100644
index 0000000..453065d
--- /dev/null
+++ b/types/encaptype.pp
@@ -0,0 +1 @@
+type Ovn::EncapType = Enum['geneve', 'vxlan']