diff --git a/src/View/Requirements_Backend.php b/src/View/Requirements_Backend.php
index f41ef33c3..fa5a26b5e 100644
--- a/src/View/Requirements_Backend.php
+++ b/src/View/Requirements_Backend.php
@@ -219,6 +219,7 @@ class Requirements_Backend
     /**
      * Gets the minification service for this backend
      *
+     * @deprecated 4.0..5.0
      * @return Requirements_Minifier
      */
     public function getMinifier()
diff --git a/src/View/Requirements_Minifier.php b/src/View/Requirements_Minifier.php
index 0994d639c..5fc16c413 100644
--- a/src/View/Requirements_Minifier.php
+++ b/src/View/Requirements_Minifier.php
@@ -4,6 +4,8 @@ namespace SilverStripe\View;
 
 /**
  * Provides an abstract interface for minifying content
+ *
+ * @deprecated 4.0..5.0
  */
 interface Requirements_Minifier
 {