diff --git a/jobs/uaa/spec b/jobs/uaa/spec
index cc4ae2836..e9de2ae66 100644
--- a/jobs/uaa/spec
+++ b/jobs/uaa/spec
@@ -1304,8 +1304,12 @@ properties:
       BTADAQH/MA0GCSqGSIb3DQEBBQUAA4GBAL5j1JCN5EoXMOOBSBUL8KeVZFQD3Nfy
       YkYKBatFEKdBFlAKLBdG+5KzE7sTYesn7EzBISHXFz3DhdK2tg+IF1DeSFVmFl2n
       iVxQ1sYjo4kCugHBsWo+MpFH9VBLFzsMlP3eIDuVKe8aPXFKYCGhctZEJdQTKlja
-      lshe50nayKrT
-      -----END CERTIFICATE----
+            lshe50nayKrT
+            -----END CERTIFICATE----
+
+  uaa.mtls_enabled:
+    description: "Enable RFC 8705 mTLS client authentication at /oauth/mtls/token. Requires Gorouter forwarded_client_cert: sanitize_set."
+    default: false
   login.saml.providers:
     description: |
       Contains a hash of SAML Identity Providers,
diff --git a/jobs/uaa/templates/config/uaa.yml.erb b/jobs/uaa/templates/config/uaa.yml.erb
index 2ef225569..958d776b8 100644
--- a/jobs/uaa/templates/config/uaa.yml.erb
+++ b/jobs/uaa/templates/config/uaa.yml.erb
@@ -369,6 +369,13 @@
       client.each do |key,value|
         client_data[key] = value
       end
+      has_mtls_ca = client_data['tls-client-auth-ca'].is_a?(String) &&
+          !client_data['tls-client-auth-ca'].strip.empty?
+      client_data.delete('tls-client-auth-trusted-proxy-ca') if
+          client_data['tls-client-auth-trusted-proxy-ca'].is_a?(String) &&
+          client_data['tls-client-auth-trusted-proxy-ca'].strip.empty?
+      message = message + "\nInvalid property: uaa.clients.#{id}.token-endpoint-auth-method" if
+          client_data.key?('token-endpoint-auth-method')
       if !client['scopes'].nil?
         client_data.delete('scopes')
         if client['scopes'].is_a? Array
@@ -380,7 +387,10 @@
       if is_missing(client_data, 'authorized-grant-types')
         message = message + "\nMissing property: uaa.clients.#{id}.authorized-grant-types"
       else
-        message = message + "\nMissing property: uaa.clients.#{id}.secret" if client_data['secret'].nil? && client_data['authorized-grant-types'] != 'implicit'
+        message = message + "\nMissing property: uaa.clients.#{id}.secret" if
+            client_data['secret'].nil? &&
+            client_data['authorized-grant-types'] != 'implicit' &&
+            !has_mtls_ca
         if (client_data['redirect-uri'].nil? || client_data['redirect-uri'].empty?)
           message = message + "\nMissing property: uaa.clients.#{id}.redirect-uri" if client_data['authorized-grant-types'] =~ /implicit|authorization_code/
         elsif client_data['redirect-uri'].split(',').any? { |uri| !(uri =~ /^http(\*|s)?:\/\/(.*:.*@)?(([a-zA-Z0-9\-\*]+\.)*[a-zA-Z0-9\-]+\.)?[a-zA-Z0-9\-]+(:[0-9]+)?(\/.*|$)/) }
@@ -653,6 +663,7 @@
         'sleep' => p('uaa.shutdown.sleep')
       },
       'url' => uaa_base,
+      'mtls-enabled' => p('uaa.mtls_enabled'),
       'limitedFunctionality' => {
         'statusFile' => p('uaa.limitedFunctionality.statusFile'),
         'whitelist' => {
diff --git a/spec/uaa-release.erb_spec.rb b/spec/uaa-release.erb_spec.rb
index d04fe1547..270eb9c32 100755
--- a/spec/uaa-release.erb_spec.rb
+++ b/spec/uaa-release.erb_spec.rb
@@ -183,6 +183,19 @@ def str_compare(output, actual)
       end
     end
 
+    context 'when mTLS is enabled' do
+      let(:input) {'spec/input/test-defaults.yml'}
+      let(:erb_template) {'../jobs/uaa/templates/config/uaa.yml.erb'}
+
+      before do
+        generated_cf_manifest['properties']['uaa']['mtls_enabled'] = true
+      end
+
+      it 'does not render a configurable mtls endpoint block' do
+        expect(parsed_yaml).not_to have_key('mtls')
+      end
+    end
+
     context 'for deprecated-properties-still-work.yml' do
       let(:input) {'spec/input/deprecated-properties-still-work.yml'}
       let(:output_uaa) {'spec/compare/deprecated-properties-still-work-uaa.yml'}
@@ -1261,6 +1274,50 @@ def str_compare(output, actual)
         end
       end
 
+      context 'client_credentials mTLS clients' do
+        let(:erb_template) {'../jobs/uaa/templates/config/uaa.yml.erb'}
+
+        before do
+          client = generated_cf_manifest['properties']['uaa']['clients']['app']
+          client['authorized-grant-types'] = 'client_credentials'
+          client.delete('secret')
+        end
+
+        it 'allows a secretless client with a nonblank tls-client-auth-ca' do
+          generated_cf_manifest['properties']['uaa']['clients']['app']['tls-client-auth-ca'] = "-----BEGIN CERTIFICATE-----\nCA\n-----END CERTIFICATE-----"
+
+          expect { parsed_yaml }.not_to raise_error
+        end
+
+        it 'omits a blank tls-client-auth-trusted-proxy-ca' do
+          generated_cf_manifest['properties']['uaa']['clients']['app']['tls-client-auth-trusted-proxy-ca'] = ' '
+
+          expect(parsed_yaml['oauth']['clients']['app']).not_to have_key('tls-client-auth-trusted-proxy-ca')
+        end
+
+        it 'requires a secret when tls-client-auth-ca is absent' do
+          expect {
+            parsed_yaml
+          }.to raise_error(ArgumentError, /Missing property: uaa.clients.app.secret/)
+        end
+
+        it 'requires a secret when tls-client-auth-ca is blank' do
+          generated_cf_manifest['properties']['uaa']['clients']['app']['tls-client-auth-ca'] = ' '
+
+          expect {
+            parsed_yaml
+          }.to raise_error(ArgumentError, /Missing property: uaa.clients.app.secret/)
+        end
+
+        it 'does not exempt a client with private-key trust configuration from requiring a secret' do
+          generated_cf_manifest['properties']['uaa']['clients']['app']['client_jwt_config'] = '{}'
+
+          expect {
+            parsed_yaml
+          }.to raise_error(ArgumentError, /Missing property: uaa.clients.app.secret/)
+        end
+      end
+
       context 'redirect-uri is missing from required grant types' do
         let(:erb_template) {'../jobs/uaa/templates/config/uaa.yml.erb'}
         grant_types_requiring_secret = ['authorization_code', 'implicit']
diff --git a/src/uaa b/src/uaa
index 5d42e16ae..aeb439805 160000
--- a/src/uaa
+++ b/src/uaa
@@ -1 +1 @@
-Subproject commit 5d42e16ae2771a80f5e8818125e971d3b56cd09f
+Subproject commit aeb43980599ea9c4b4f1104d59e3661c53a2caff