diff --git a/acp/portal_module.php b/acp/portal_module.php
index 9166bba9..277416c8 100644
--- a/acp/portal_module.php
+++ b/acp/portal_module.php
@@ -448,7 +448,7 @@ class portal_module
 						}
 
 						// do not install if module already exists in that column
-						if (!$submit && $module_classname != 'custom')
+						if (!$submit && $module_classname != '\board3\portal\modules\custom')
 						{
 							trigger_error($this->user->lang['MODULE_ADD_ONCE'] . adm_back_link($this->u_action), E_USER_WARNING);
 						}
@@ -579,6 +579,27 @@ class portal_module
 						'S_MODULE_NAMES'	=> $options,
 						'S_HIDDEN_FIELDS'	=> $s_hidden_fields,
 					));
+
+					if ($this->request->is_ajax())
+					{
+						$this->template->assign_vars(array(
+							'S_AJAX_REQUEST'	=> true,
+							'U_ACTION'		=> str_replace('&', '&', $this->get_module_link('modules', $module_id)),
+						));
+						$this->template->set_filenames(array(
+							'body' => 'portal/acp_portal_modules.html')
+						);
+						$json_response = new \phpbb\json_response;
+						$json_response->send(array(
+							'MESSAGE_BODY'		=> $this->template->assign_display('body'),
+							'MESSAGE_TITLE'		=> $this->user->lang['ADD_MODULE'],
+							'MESSAGE_TEXT'		=> $this->user->lang['ADD_MODULE'],
+
+							'YES_VALUE'		=> $this->user->lang['SUBMIT'],
+							'S_CONFIRM_ACTION'	=> str_replace('&', '&', $this->get_module_link('modules', $module_id)), //inefficient, rewrite whole function
+							'S_HIDDEN_FIELDS'	=> $s_hidden_fields
+						));
+					}
 				}
 				else
 				{
diff --git a/adm/style/portal/acp_portal_modules.html b/adm/style/portal/acp_portal_modules.html
index 3532a8e2..8f2cc80b 100644
--- a/adm/style/portal/acp_portal_modules.html
+++ b/adm/style/portal/acp_portal_modules.html
@@ -1,14 +1,31 @@
+<!-- IF S_AJAX_REQUEST -->
+	<form id="acp_portal_modules" method="post" action="{U_ACTION}">
+		<fieldset>
+			<dl>
+				<dt><label for="module_classname" style="display: inline;">{L_CHOOSE_MODULE}:</label><br /><span>{L_CHOOSE_MODULE_EXP}</span></dt>
+				<dd><select name="module_classname" id="module_classname">{S_MODULE_NAMES}</select></dd>
+			</dl>
+
+			<p class="submit-buttons">
+				<input class="button1" type="submit" id="submit" name="submit" value="{L_SUBMIT}" />&nbsp;
+				<input class="button2" type="reset" id="reset" name="reset" value="{L_RESET}" />
+				{S_FORM_TOKEN}{S_HIDDEN_FIELDS}
+			</p>
+		</fieldset>
+	</form>
+
+<!-- ELSE -->
 <!-- INCLUDE overall_header.html -->
 
 <a name="maincontent"></a>
 
 <!-- IF S_EDIT -->
+
 <h1>{L_ACP_PORTAL_MODULES}</h1>
 <p>{L_ACP_PORTAL_MODULES_EXP}</p>
 
 <form id="acp_portal_modules" method="post" action="{U_ACTION}">
 	<fieldset>
-		<legend>{L_GENERAL_OPTIONS}</legend>
 		<dl>
 			<dt><label for="module_classname">{L_CHOOSE_MODULE}:</label><br /><span>{L_CHOOSE_MODULE_EXP}</span></dt>
 			<dd><select name="module_classname" id="module_classname">{S_MODULE_NAMES}</select></dd>
@@ -27,7 +44,7 @@
 <h1>{L_ACP_PORTAL_MODULES}</h1>
 <p>{L_ACP_PORTAL_MODULES_EXP}</p>
 
-<form id="acp_portal_modules" method="post" action="{U_ACTION}">
+<form id="acp_portal_modules" method="post" action="{U_ACTION}" data-ajax="true">
 	<fieldset class="tabulated">
 	<legend>{L_ACP_PORTAL_MODULES}</legend>
 
@@ -172,4 +189,5 @@
 
 <!-- ENDIF -->
 
-<!-- INCLUDE overall_footer.html -->
\ No newline at end of file
+<!-- INCLUDE overall_footer.html -->
+<!-- ENDIF -->
\ No newline at end of file