diff --git a/framework/data/ActiveDataProvider.php b/framework/data/ActiveDataProvider.php
index a46a8a30851..357b1eb74ef 100644
--- a/framework/data/ActiveDataProvider.php
+++ b/framework/data/ActiveDataProvider.php
@@ -164,7 +164,7 @@ protected function prepareTotalCount()
         $query = (clone $this->query)->limit(-1)->offset(-1)->orderBy([]);
         $key = md5((string)$query);
 
-        if (isset($this->_totalCount[$key]) === false) {
+        if (!array_key_exists($key, $this->_totalCount)) {
             $this->_totalCount[$key] = (int)$query->count('*', $this->db);
         }
         return $this->_totalCount[$key];
diff --git a/framework/data/Pagination.php b/framework/data/Pagination.php
index 08c12a351cc..372c35000e5 100644
--- a/framework/data/Pagination.php
+++ b/framework/data/Pagination.php
@@ -142,7 +142,7 @@ class Pagination extends BaseObject implements Linkable
      */
     private $_pageSize;
     /**
-     * @var Closure|int return total number of items.
+     * @var Closure|int total number of items or closure returning it.
      */
     private $_totalCount = 0;
 
@@ -353,7 +353,7 @@ public function getTotalCount()
         if (is_numeric($this->_totalCount)) {
             return (int)$this->_totalCount;
         }
-        return (int)call_user_func($this->_totalCount);
+        return (int)$this->_totalCount();
     }
 
     /**