diff --git a/config.xsd b/config.xsd
index 1b8519c31..6e6d82868 100644
--- a/config.xsd
+++ b/config.xsd
@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <xs:schema
-        xmlns:xs="http://www.w3.org/2001/XMLSchema"
-        xmlns="https://getpsalm.org/schema/config"
-        targetNamespace="https://getpsalm.org/schema/config"
-        elementFormDefault="qualified"
+    xmlns:xs="http://www.w3.org/2001/XMLSchema"
+    xmlns="https://getpsalm.org/schema/config"
+    targetNamespace="https://getpsalm.org/schema/config"
+    elementFormDefault="qualified"
 >
     <xs:element name="psalm" type="PsalmType" />
 
diff --git a/psalm.xml.dist b/psalm.xml.dist
index a29f052ca..0cf1ba819 100644
--- a/psalm.xml.dist
+++ b/psalm.xml.dist
@@ -7,7 +7,8 @@
     rememberPropertyAssignmentsAfterCall="true"
     throwExceptionOnError="0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="config.xsd"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config config.xsd"
 >
     <projectFiles>
         <directory name="src" />
diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index abe991e64..6a64aa497 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -362,6 +362,25 @@ class Config
         $dom_document = new \DOMDocument();
         $dom_document->loadXML($file_contents);
 
+        $psalm_nodes = $dom_document->getElementsByTagName('psalm');
+
+        /** @var \DomElement|null */
+        $psalm_node = $psalm_nodes->item(0);
+
+        if (!$psalm_node) {
+            throw new ConfigException(
+                'Missing psalm node'
+            );
+        }
+
+        if (!$psalm_node->hasAttribute('xmlns')) {
+            $psalm_node->setAttribute('xmlns', 'https://getpsalm.org/schema/config');
+
+            $old_dom_document = $dom_document;
+            $dom_document = new \DOMDocument();
+            $dom_document->loadXML($old_dom_document->saveXml());
+        }
+
         // Enable user error handling
         libxml_use_internal_errors(true);