diff --git a/manifests/init.pp b/manifests/init.pp
index 551a070e..0fb4b87a 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -239,6 +239,10 @@
 #   HTTPProxyToWSGI middleware.
 #   Defaults to $::os_service_default.
 #
+# [*max_request_body_size*]
+#   (Optional) Set max request body size
+#   Defaults to $::os_service_default.
+#
 # [*heat_clients_url*]
 #   (optional) Heat url in format like http://0.0.0.0:8004/v1/%(tenant_id)s.
 #   Defaults to $::os_service_default.
@@ -326,6 +330,7 @@ class heat(
   $notification_driver                = $::os_service_default,
   $notification_topics                = $::os_service_default,
   $enable_proxy_headers_parsing       = $::os_service_default,
+  $max_request_body_size              = $::os_service_default,
   $heat_clients_url                   = $::os_service_default,
   $heat_clients_endpoint_type         = $::os_service_default,
   $purge_config                       = false,
@@ -445,6 +450,7 @@ class heat(
 
   oslo::middleware { 'heat_config':
     enable_proxy_headers_parsing => $enable_proxy_headers_parsing,
+    max_request_body_size        => $max_request_body_size,
   }
 
 }
diff --git a/releasenotes/notes/max_request_body_size-86ae2a0048a67496.yaml b/releasenotes/notes/max_request_body_size-86ae2a0048a67496.yaml
new file mode 100644
index 00000000..f29fec52
--- /dev/null
+++ b/releasenotes/notes/max_request_body_size-86ae2a0048a67496.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Add support to configure `[oslo_middleware]/max_request_body_size` with
+    `$max_request_body_size`.
diff --git a/spec/classes/heat_init_spec.rb b/spec/classes/heat_init_spec.rb
index bd8311e7..4c929270 100644
--- a/spec/classes/heat_init_spec.rb
+++ b/spec/classes/heat_init_spec.rb
@@ -143,6 +143,7 @@ describe 'heat' do
     it 'sets default value for http_proxy_to_wsgi middleware' do
       is_expected.to contain_oslo__middleware('heat_config').with(
         :enable_proxy_headers_parsing => '<SERVICE DEFAULT>',
+        :max_request_body_size        => '<SERVICE DEFAULT>',
       )
     end