diff --git a/etc/adminhtml/system.xml b/etc/adminhtml/system.xml
index 6e0a98f..0c8e79d 100644
--- a/etc/adminhtml/system.xml
+++ b/etc/adminhtml/system.xml
@@ -23,6 +23,7 @@
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
     <system>
+        <!-- Prefix "piwik/" left for compatibility with Henhed_Piwik -->
         <section id="piwik"
                  translate="label"
                  type="text"
diff --git a/etc/config.xml b/etc/config.xml
index 9cc5a69..e932950 100644
--- a/etc/config.xml
+++ b/etc/config.xml
@@ -23,6 +23,7 @@
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
     <default>
+        <!-- Prefix "piwik/" left for compatibility with Henhed_Piwik -->
         <piwik>
             <tracking>
                 <enabled>0</enabled>