diff --git a/Classes/PHPExcel/Shared/JAMA/Matrix.php b/Classes/PHPExcel/Shared/JAMA/Matrix.php
index c168567..ca2fa0a 100644
--- a/Classes/PHPExcel/Shared/JAMA/Matrix.php
+++ b/Classes/PHPExcel/Shared/JAMA/Matrix.php
@@ -1012,7 +1012,7 @@ class Matrix {
 							$M->set($i, $j, $this->A[$i][$j] / $value);
 						}
 					} else {
-						$this->A[$i][$j] = PHPExcel_Calculation_Functions::NaN();
+						$M->set($i, $j, PHPExcel_Calculation_Functions::NaN());
 					}
 				}
 			}
diff --git a/changelog.txt b/changelog.txt
index 9aaa195..941e2bb 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -25,7 +25,7 @@
 
 Fixed in SVN:
 - Feature:  (MBaker) Support for Extended Workbook Properties in Excel2007, Excel5 and OOCalc Readers; support for User-defined Workbook Properties in Excel2007 and OOCalc Readers
-
+- Bugfix:   (MB) Work item 14143 - NA() doesn't propagate in matrix calc - quick fix in JAMA/Matrix.php
 
 2010-08-26 (v1.7.4):
 - Bugfix:   (Progi1984) Workitem 7895 - Excel5 : Formula : Power