diff --git a/manifests/wsgi/apache.pp b/manifests/wsgi/apache.pp
index 267a74ce..2c92fc5e 100644
--- a/manifests/wsgi/apache.pp
+++ b/manifests/wsgi/apache.pp
@@ -66,6 +66,9 @@
 #     apache::vhost ssl parameters.
 #     Optional. Default to apache::vhost 'ssl_*' defaults.
 #
+#   [*vhost_custom_fragment*]
+#     (optional) Additional vhost configuration, if applicable.
+#
 # == Dependencies
 #
 #   requires Class['apache'] & Class['heat']
@@ -78,20 +81,21 @@
 #
 define heat::wsgi::apache (
   $port,
-  $servername    = $::fqdn,
-  $bind_host     = undef,
-  $path          = '/',
-  $ssl           = true,
-  $workers       = 1,
-  $ssl_cert      = undef,
-  $ssl_key       = undef,
-  $ssl_chain     = undef,
-  $ssl_ca        = undef,
-  $ssl_crl_path  = undef,
-  $ssl_crl       = undef,
-  $ssl_certs_dir = undef,
-  $threads       = $::os_workers,
-  $priority      = '10',
+  $servername            = $::fqdn,
+  $bind_host             = undef,
+  $path                  = '/',
+  $ssl                   = true,
+  $workers               = 1,
+  $ssl_cert              = undef,
+  $ssl_key               = undef,
+  $ssl_chain             = undef,
+  $ssl_ca                = undef,
+  $ssl_crl_path          = undef,
+  $ssl_crl               = undef,
+  $ssl_certs_dir         = undef,
+  $threads               = $::os_workers,
+  $priority              = '10',
+  $vhost_custom_fragment = undef,
 ) {
   if $title !~ /^api(|_cfn|_cloudwatch)$/ {
     fail('The valid options are api, api_cfn, api_cloudwatch')
@@ -129,5 +133,6 @@ define heat::wsgi::apache (
     wsgi_script_source    => getvar("::heat::params::heat_${title}_wsgi_script_source"),
     allow_encoded_slashes => 'on',
     require               => Anchor['heat::install::end'],
+    vhost_custom_fragment => $vhost_custom_fragment,
   }
 }
diff --git a/manifests/wsgi/apache_api_cfn.pp b/manifests/wsgi/apache_api_cfn.pp
index 1cba07fe..8be184d1 100644
--- a/manifests/wsgi/apache_api_cfn.pp
+++ b/manifests/wsgi/apache_api_cfn.pp
@@ -89,6 +89,10 @@ class heat::wsgi::apache_api_cfn (
   $priority      = '10',
 ) {
 
+  # See custom fragment below
+  include ::apache
+  include ::apache::mod::headers
+
   validate_integer($port)
 
   # Workaround for https://bugzilla.redhat.com/show_bug.cgi?id=1396553
@@ -99,21 +103,24 @@ class heat::wsgi::apache_api_cfn (
       notify => Heat::Wsgi::Apache['api_cfn'],
     }
   }
+
   heat::wsgi::apache { 'api_cfn':
-    port          => $port,
-    servername    => $servername,
-    bind_host     => $bind_host,
-    path          => $path,
-    ssl           => $ssl,
-    workers       => $workers,
-    ssl_cert      => $ssl_cert,
-    ssl_key       => $ssl_key,
-    ssl_chain     => $ssl_chain,
-    ssl_ca        => $ssl_ca,
-    ssl_crl_path  => $ssl_crl_path,
-    ssl_crl       => $ssl_crl,
-    ssl_certs_dir => $ssl_certs_dir,
-    threads       => $threads,
-    priority      => $priority,
+    port                  => $port,
+    servername            => $servername,
+    bind_host             => $bind_host,
+    path                  => $path,
+    ssl                   => $ssl,
+    workers               => $workers,
+    ssl_cert              => $ssl_cert,
+    ssl_key               => $ssl_key,
+    ssl_chain             => $ssl_chain,
+    ssl_ca                => $ssl_ca,
+    ssl_crl_path          => $ssl_crl_path,
+    ssl_crl               => $ssl_crl,
+    ssl_certs_dir         => $ssl_certs_dir,
+    threads               => $threads,
+    priority              => $priority,
+    # Enforce content-type, see https://bugs.launchpad.net/tripleo/+bug/1641589
+    vhost_custom_fragment => 'RequestHeader set Content-Type "application/json"',
   }
 }