diff --git a/src/java/org/apache/poi/ss/usermodel/DataFormatter.java b/src/java/org/apache/poi/ss/usermodel/DataFormatter.java
index c041e3237..3f09aafa2 100644
--- a/src/java/org/apache/poi/ss/usermodel/DataFormatter.java
+++ b/src/java/org/apache/poi/ss/usermodel/DataFormatter.java
@@ -983,7 +983,7 @@ public class DataFormatter {
        public String format(Number num) {
           double wholePart = Math.floor(num.doubleValue());
           double decPart = num.doubleValue() - wholePart;
-          if (wholePart * decPart == 0) {
+          if (wholePart + decPart == 0) {
              return "0";
           }