diff --git a/2.3.x/install.xml b/2.3.x/install.xml
index cf6b1f4..38f2691 100644
--- a/2.3.x/install.xml
+++ b/2.3.x/install.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?> 
 <modification>
     <name>Antispam by Cleantalk</name>
-    <version>1.5</version>
+    <version>1.6</version>
     <author>Cleantalk Inc.</author>
     <link>https://cleantalk.org/</link>
     <code>antispambycleantalk</code>
@@ -147,7 +147,7 @@
         <file path="catalog/view/theme/*/template/common/header.tpl">
         <operation>
             <search><![CDATA[<?php foreach ($scripts as $script) { ?>]]></search>
-            <add position="before"><![CDATA[<script src="catalog/view/javascript/antispambycleantalk.js?v=1.5" type="text/javascript"></script>]]></add>            
+            <add position="before"><![CDATA[<script src="catalog/view/javascript/antispambycleantalk.js?v=1.6" type="text/javascript"></script>]]></add>            
         </operation>
     </file>        
 </modification>
diff --git a/2.3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php b/2.3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php
index a915fa6..f873603 100644
--- a/2.3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php
+++ b/2.3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php
@@ -3,7 +3,7 @@
 
 class CleantalkFuncs
 {
-    const ENGINE = 'opencart-15';
+    const ENGINE = 'opencart-16';
 
     private $ct_access_key = '';
 
diff --git a/2.x - 2.2.x/install.xml b/2.x - 2.2.x/install.xml
index f251080..04dc89e 100644
--- a/2.x - 2.2.x/install.xml	
+++ b/2.x - 2.2.x/install.xml	
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?> 
 <modification>
     <name>Antispam by Cleantalk</name>
-    <version>1.5</version>
+    <version>1.6</version>
     <author>Cleantalk Inc.</author>
     <link>https://cleantalk.org/</link>
     <code>antispambycleantalk</code>
@@ -147,7 +147,7 @@
         <file path="catalog/view/theme/*/template/common/header.tpl">
         <operation>
             <search><![CDATA[<?php foreach ($scripts as $script) { ?>]]></search>
-            <add position="before"><![CDATA[<script src="catalog/view/javascript/antispambycleantalk.js?v=1.5" type="text/javascript"></script>]]></add>            
+            <add position="before"><![CDATA[<script src="catalog/view/javascript/antispambycleantalk.js?v=1.6" type="text/javascript"></script>]]></add>            
         </operation>
     </file>            
 </modification>
diff --git a/2.x - 2.2.x/upload/catalog/controller/module/cleantalk.funcs.php b/2.x - 2.2.x/upload/catalog/controller/module/cleantalk.funcs.php
index bb52d10..4145fe7 100644
--- a/2.x - 2.2.x/upload/catalog/controller/module/cleantalk.funcs.php	
+++ b/2.x - 2.2.x/upload/catalog/controller/module/cleantalk.funcs.php	
@@ -3,7 +3,7 @@
 
 class CleantalkFuncs
 {
-    const ENGINE = 'opencart-15';
+    const ENGINE = 'opencart-16';
 
     private $ct_access_key = '';
 
diff --git a/3.x/install.xml b/3.x/install.xml
index b835810..75dbe60 100644
--- a/3.x/install.xml
+++ b/3.x/install.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?> 
 <modification>
     <name>Antispam by Cleantalk</name>
-    <version>1.5</version>
+    <version>1.6</version>
     <author>Cleantalk Inc.</author>
     <link>https://cleantalk.org/</link>
     <code>antispambycleantalk</code>
@@ -147,7 +147,7 @@
         <file path="catalog/view/theme/*/template/common/header.twig">
         <operation>
             <search><![CDATA[{% for script in scripts %}]]></search>
-            <add position="before"><![CDATA[<script src="catalog/view/javascript/antispambycleantalk.js?v=1.5" type="text/javascript"></script>]]></add>            
+            <add position="before"><![CDATA[<script src="catalog/view/javascript/antispambycleantalk.js?v=1.6" type="text/javascript"></script>]]></add>            
         </operation>
     </file>    
 </modification>
diff --git a/3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php b/3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php
index a915fa6..f873603 100644
--- a/3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php
+++ b/3.x/upload/catalog/controller/extension/module/cleantalk.funcs.php
@@ -3,7 +3,7 @@
 
 class CleantalkFuncs
 {
-    const ENGINE = 'opencart-15';
+    const ENGINE = 'opencart-16';
 
     private $ct_access_key = '';
 
diff --git a/README.md b/README.md
index c447712..f966cc3 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # opencart-antispam
 Opencart anti-spam extension.
-# Version 1.5
+# Version 1.6
 
 ## How to install