diff --git a/src/Pixie/QueryBuilder/QueryBuilderHandler.php b/src/Pixie/QueryBuilder/QueryBuilderHandler.php
index 134fba0..065cb4f 100644
--- a/src/Pixie/QueryBuilder/QueryBuilderHandler.php
+++ b/src/Pixie/QueryBuilder/QueryBuilderHandler.php
@@ -258,10 +258,12 @@ protected function aggregate($type)
             unset($this->statements['selects']);
         }
 
-        if (is_array($row[0])) {
-            return (int) $row[0]['field'];
-        } elseif (is_object($row[0])) {
-            return (int) $row[0]->field;
+        if (isset($row[0])) {
+            if (is_array($row[0])) {
+                return (int) $row[0]['field'];
+            } elseif (is_object($row[0])) {
+                return (int) $row[0]->field;
+            }
         }
 
         return 0;