diff --git a/src/StringTagField.php b/src/StringTagField.php
index e34d1a4..3b280bb 100644
--- a/src/StringTagField.php
+++ b/src/StringTagField.php
@@ -379,7 +379,7 @@ class StringTagField extends DropdownField
      */
     public function validate($validator)
     {
-        return true;
+        return $this->extendValidationResult(true, $validator);
     }
 
     /**
diff --git a/src/TagField.php b/src/TagField.php
index 16104d3..99bd8fa 100644
--- a/src/TagField.php
+++ b/src/TagField.php
@@ -572,7 +572,7 @@ class TagField extends MultiSelectField
      */
     public function validate($validator)
     {
-        return true;
+        return $this->extendValidationResult(true, $validator);
     }
 
     /**