diff --git a/Classes/PHPExcel/Calculation.php b/Classes/PHPExcel/Calculation.php
index b12c960a..df6c68b7 100644
--- a/Classes/PHPExcel/Calculation.php
+++ b/Classes/PHPExcel/Calculation.php
@@ -3590,6 +3590,7 @@ class PHPExcel_Calculation {
 	// trigger an error, but nicely, if need be
 	protected function _raiseFormulaError($errorMessage) {
 		$this->formulaError = $errorMessage;
+		$this->debugLogStack = array();
 		if (!$this->suppressFormulaErrors) throw new Exception($errorMessage);
 		trigger_error($errorMessage, E_USER_ERROR);
 	}	//	function _raiseFormulaError()
diff --git a/changelog.txt b/changelog.txt
index 772db20f..df096888 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -42,6 +42,7 @@ Fixed in SVN:
 - Bugfix:   (MBaker) Work item 16643 - Bug In Cache System (cell reference when throwing caching errors)
 - Bugfix:   (MBaker) Work item 16895 - PHP Invalid index notice on writing excel file when active sheet has been deleted
 - Bugfix:   (MBaker) Work item 16956 - External links in Excel2010 files cause Fatal error
+- Bugfix:   (MBaker) Work item 16960 - Previous calculation engine error conditions trigger cyclic reference errors
 - General:  (MBaker) Work item 15405 - Two easy to fix Issues concerning PHPExcel_Token_Stack (l10n/UC)
 - General:  (MBaker) Work item 15461 - Locale file paths not fit for windows
 - General:  (MBaker) Work item 16643 - Add file directory as a cache option for cache_to_discISAM