diff --git a/includes/sanitizers/class-amp-base-sanitizer.php b/includes/sanitizers/class-amp-base-sanitizer.php
index 88701b55744..605ed540c93 100644
--- a/includes/sanitizers/class-amp-base-sanitizer.php
+++ b/includes/sanitizers/class-amp-base-sanitizer.php
@@ -320,7 +320,7 @@ public function remove_child( $child ) {
 		if ( method_exists( $child->parentNode, 'removeChild' ) ) { // phpcs:ignore WordPress.NamingConventions.ValidVariableName.NotSnakeCaseMemberVar.
 			$child->parentNode->removeChild( $child ); // phpcs:ignore WordPress.NamingConventions.ValidVariableName.NotSnakeCaseMemberVar.
 			if ( isset( $this->args['mutation_callback'] ) ) {
-				call_user_func( $this->args['mutation_callback'], $child, 'removed' );
+				call_user_func( $this->args['mutation_callback'], $child, AMP_Validation_Utils::NODE_REMOVED );
 			}
 		}
 	}
@@ -341,7 +341,7 @@ public function remove_attribute( $node, $attribute ) {
 		if ( method_exists( $node, 'removeAttribute' ) ) {
 			$node->removeAttribute( $attribute );
 			if ( isset( $this->args['mutation_callback'] ) ) {
-				call_user_func( $this->args['mutation_callback'], $node, 'removed_attr', $attribute );
+				call_user_func( $this->args['mutation_callback'], $node, AMP_Validation_Utils::ATTRIBUTE_REMOVED, $attribute );
 			}
 		}
 	}
diff --git a/includes/sanitizers/class-amp-tag-and-attribute-sanitizer.php b/includes/sanitizers/class-amp-tag-and-attribute-sanitizer.php
index c55a8b1c9fb..80c36aaac1e 100644
--- a/includes/sanitizers/class-amp-tag-and-attribute-sanitizer.php
+++ b/includes/sanitizers/class-amp-tag-and-attribute-sanitizer.php
@@ -705,7 +705,7 @@ private function sanitize_disallowed_attributes_in_node( $node, $attr_spec_list
 		foreach ( $attrs_to_remove as $attr ) {
 			$node->removeAttributeNode( $attr );
 			if ( isset( $this->args['mutation_callback'], $attr->name ) ) {
-				call_user_func( $this->args['mutation_callback'], $node, 'removed_attr', $attr->name );
+				call_user_func( $this->args['mutation_callback'], $node, AMP_Validation_Utils::ATTRIBUTE_REMOVED, $attr->name );
 			}
 		}
 	}