diff --git a/src/PhpSpreadsheet/Calculation/Calculation.php b/src/PhpSpreadsheet/Calculation/Calculation.php
index 344bc323..f428c9b4 100644
--- a/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -3737,7 +3737,7 @@ class Calculation
             } elseif (isset(self::$operators[$opCharacter]) && !$expectingOperator) {
                 return $this->raiseFormulaError("Formula Error: Unexpected operator '$opCharacter'");
             } else {    // I don't even want to know what you did to get here
-                return $this->raiseFormulaError('Formula Error: An unexpected error occured');
+                return $this->raiseFormulaError('Formula Error: An unexpected error occurred');
             }
             //    Test for end of formula string
             if ($index == strlen($formula)) {