diff --git a/SeedDMS_Core/Core/inc.ClassDocument.php b/SeedDMS_Core/Core/inc.ClassDocument.php
index 8a72a9961..d89a3fe9c 100644
--- a/SeedDMS_Core/Core/inc.ClassDocument.php
+++ b/SeedDMS_Core/Core/inc.ClassDocument.php
@@ -1861,9 +1861,9 @@ class SeedDMS_Core_Document extends SeedDMS_Core_Object { /* {{{ */
 		/* Check if 'onPreRemoveDocument' callback is set */
 		if(isset($this->_dms->callbacks['onPreRemoveDocument'])) {
 			foreach($this->_dms->callbacks['onPreRemoveDocument'] as $callback) {
-				if(!call_user_func($callback[0], $callback[1], $this)) {
-					return false;
-				}
+				$ret = call_user_func($callback[0], $callback[1], $this);
+				if(is_bool($ret))
+					return $ret;
 			}
 		}
 
diff --git a/SeedDMS_Core/Core/inc.ClassFolder.php b/SeedDMS_Core/Core/inc.ClassFolder.php
index f92bb8ff2..983d5ca49 100644
--- a/SeedDMS_Core/Core/inc.ClassFolder.php
+++ b/SeedDMS_Core/Core/inc.ClassFolder.php
@@ -882,9 +882,9 @@ class SeedDMS_Core_Folder extends SeedDMS_Core_Object {
 		/* Check if 'onPreRemoveFolder' callback is set */
 		if(isset($this->_dms->callbacks['onPreRemoveFolder'])) {
 			foreach($this->_dms->callbacks['onPreRemoveFolder'] as $callback) {
-				if(!call_user_func($callback[0], $callback[1], $this)) {
-					return false;
-				}
+				$ret = call_user_func($callback[0], $callback[1], $this);
+				if(is_bool($ret))
+					return $ret;
 			}
 		}