diff --git a/Classes/PHPExcel/Calculation/LookupRef.php b/Classes/PHPExcel/Calculation/LookupRef.php
index 94f42e5f..75e7f69c 100644
--- a/Classes/PHPExcel/Calculation/LookupRef.php
+++ b/Classes/PHPExcel/Calculation/LookupRef.php
@@ -735,11 +735,7 @@ class PHPExcel_Calculation_LookupRef {
 				return PHPExcel_Calculation_Functions::NA();
 			} else {
 				//	otherwise return the appropriate value
-				$result = $lookup_array[$rowNumber][$returnColumn];
-				if ((is_numeric($lookup_value) && is_numeric($result)) ||
-					(!is_numeric($lookup_value) && !is_numeric($result))) {
-					return $result;
-				}
+				return $lookup_array[$rowNumber][$returnColumn];
 			}
 		}
 
@@ -802,8 +798,7 @@ class PHPExcel_Calculation_LookupRef {
                 return PHPExcel_Calculation_Functions::NA();
             } else {
                 //  otherwise return the appropriate value
-                $result = $lookup_array[$returnColumn][$rowNumber];
-				return $result;
+                return $lookup_array[$returnColumn][$rowNumber];
             }
         }
 
diff --git a/changelog.txt b/changelog.txt
index d4e59470..0ae0d632 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -34,7 +34,8 @@ Planned for v1.8.1
 - Bugfix:   (MBaker)                            - Fix for percentage operator in formulae for BIFF Writer
 - Bugfix:   (MBaker)                            - Fix to getStyle() call for cell object
 - Bugfix:   (MBaker)                            - Discard Autofilters in Excel2007 Reader when filter range isn't a valid range
-- Bugfix:   (masanaikeshima)  Work Item GH-426  - Pie chart won't work in Excel 2013
+- Bugfix:   (MBaker)                            - Discard Autofilters in Excel2007 Reader when filter range isn't a valid range
+- Bugfix:   (frozenstupidity) Work Item GH-423  - Fix invalid NA return in VLOOKUP 
 - General:  (MBaker)                            - Small performance improvement for autosize columns
 - General:  (frost-nzcr4)     Work Item GH-379  - Change the getter/setter for zeroHeight to camel case
 - General:  (MBaker)          Work Item GH-394  - DefaultValueBinder is too much aggressive when converting string to numeric