diff --git a/index.js b/index.js
index add82d6..c142f9d 100755
--- a/index.js
+++ b/index.js
@@ -29,7 +29,7 @@ let buildExport = params => {
     for (let col in specification) {
       header.push({
         value: specification[col].displayName,
-        style: specification[col].headerStyle || ''
+        style: specification[col].headerStyle
       })
 
       if (specification[col].width) {
diff --git a/lib/excel.js b/lib/excel.js
index d2706d1..dba485c 100755
--- a/lib/excel.js
+++ b/lib/excel.js
@@ -19,11 +19,13 @@ function sheet_from_array_of_arrays(data, merges) {
       if(range.e.c < C) range.e.c = C;
 
       let cell;
-      if(data[R][C] && typeof data[R][C] === 'object' && data[R][C].style && !(data[R][C] instanceof Date)) {
+      if(data[R][C] && typeof data[R][C] === 'object' && !(data[R][C] instanceof Date)) {
         cell = {
           v: data[R][C].value,
-          s: data[R][C].style
         };
+        if (data[R][C].style) {
+          cell.s = data[R][C].style
+        }
       } else {
         cell = {v: data[R][C] };
       }