diff --git a/lib/loqate/phone/phone_number_validation.rb b/lib/loqate/phone/phone_number_validation.rb
index ac0cc73..4336565 100644
--- a/lib/loqate/phone/phone_number_validation.rb
+++ b/lib/loqate/phone/phone_number_validation.rb
@@ -2,7 +2,7 @@ module Loqate
   module Phone
     # Result of a phone number validation.
     class PhoneNumberValidation < Dry::Struct
-      IsValid = Types::Strict::String.enum('Yes', 'No', 'Unknown')
+      IsValid = Types::Strict::String.enum('Yes', 'No', 'Unknown', 'Maybe')
       NumberType = Types::Strict::String.enum('Mobile', 'Landline', 'Voip', 'Unknown')
 
       # The recipient phone number in international format.
diff --git a/spec/loqate/phone/phone_number_validation_spec.rb b/spec/loqate/phone/phone_number_validation_spec.rb
index 415ec0e..5d9febf 100644
--- a/spec/loqate/phone/phone_number_validation_spec.rb
+++ b/spec/loqate/phone/phone_number_validation_spec.rb
@@ -91,22 +91,18 @@
   end
 
   describe '#valid?' do
-    context 'when the validation result is Yes' do
-      subject { described_class.new(attributes.merge(is_valid: 'Yes')) }
-
-      it { is_expected.to be_valid }
-    end
+    %w[No Unknown Maybe].each do |validation_result|
+      context "when the validation result is '#{validation_result}'" do
+        subject { described_class.new(attributes.merge(is_valid: validation_result)) }
 
-    context 'when the validation result is No' do
-      subject { described_class.new(attributes.merge(is_valid: 'No')) }
-
-      it { is_expected.not_to be_valid }
+        it { is_expected.not_to be_valid }
+      end
     end
 
-    context 'when the validation result is Unknown' do
-      subject { described_class.new(attributes.merge(is_valid: 'Unknown')) }
+    context 'when the validation result is Yes' do
+      subject { described_class.new(attributes.merge(is_valid: 'Yes')) }
 
-      it { is_expected.not_to be_valid }
+      it { is_expected.to be_valid }
     end
   end
 end