diff --git a/docs/en/02_Developer_Guides/04_Configuration/00_Configuration.md b/docs/en/02_Developer_Guides/04_Configuration/00_Configuration.md
index 0cfd4bcfe..a97d2489a 100644
--- a/docs/en/02_Developer_Guides/04_Configuration/00_Configuration.md
+++ b/docs/en/02_Developer_Guides/04_Configuration/00_Configuration.md
@@ -165,6 +165,10 @@ pair in the mask is removed
 
 ## Configuration YAML Syntax and Rules
 
+<div class="alert" markdown="1">
+As of Silverstripe 4, YAML files can no longer be placed any deeper than 2 directories deep. As this was an unintended bug, this change will only affect you if you nest your modules deeper than the top level of your project.
+</div>
+
 Each module can have a directory immediately underneath the main module directory called `_config/`. Inside this 
 directory you can add YAML files that contain values for the configuration system. 
 
diff --git a/src/Core/Manifest/ConfigManifest.php b/src/Core/Manifest/ConfigManifest.php
index 6ddf1fec7..ec2986c6b 100644
--- a/src/Core/Manifest/ConfigManifest.php
+++ b/src/Core/Manifest/ConfigManifest.php
@@ -244,7 +244,9 @@ class ConfigManifest
             'min_depth' => 0,
             'name_regex'    => '/(^|[\/\\\\])_config.php$/',
             'ignore_tests'  => !$includeTests,
-            'file_callback' => array($this, 'addSourceConfigFile')
+            'file_callback' => array($this, 'addSourceConfigFile'),
+            // Cannot be max_depth: 1 due to "/framework/admin/_config.php"
+            'max_depth'     => 2
         ));
         $finder->find($this->base);
 
@@ -252,7 +254,8 @@ class ConfigManifest
         $finder->setOptions(array(
             'name_regex'    => '/\.ya?ml$/',
             'ignore_tests'  => !$includeTests,
-            'file_callback' => array($this, 'addYAMLConfigFile')
+            'file_callback' => array($this, 'addYAMLConfigFile'),
+            'max_depth'     => 2
         ));
         $finder->find($this->base);