Fix #89
diff --git a/R/add_header_above.R b/R/add_header_above.R
index 5439d75..5231c7f 100644
--- a/R/add_header_above.R
+++ b/R/add_header_above.R
@@ -94,7 +94,7 @@
   )
   header_items <- apply(header_df, 1, function(x) {
     if (trimws(x[1]) == "") {
-      paste0('<th style="border-bottom:hidden"></th>')
+      paste0('<th style="border-bottom:hidden" colspan="', x[2], '"></th>')
     } else {
       paste0('<th style="text-align:center; border-bottom:hidden; ',
              'padding-bottom:0; padding-left:3px;padding-right:3px;',
diff --git a/docs/awesome_table_in_html.html b/docs/awesome_table_in_html.html
index ed3574f..2f3154e 100644
--- a/docs/awesome_table_in_html.html
+++ b/docs/awesome_table_in_html.html
@@ -11,7 +11,7 @@
 
 <meta name="author" content="Hao Zhu" />
 
-<meta name="date" content="2017-10-24" />
+<meta name="date" content="2017-10-27" />
 
 <title>Create Awesome HTML Table with knitr::kable and kableExtra</title>
 
@@ -217,7 +217,7 @@
 
 <h1 class="title toc-ignore">Create Awesome HTML Table with knitr::kable and kableExtra</h1>
 <h4 class="author"><em>Hao Zhu</em></h4>
-<h4 class="date"><em>2017-10-24</em></h4>
+<h4 class="date"><em>2017-10-27</em></h4>
 
 </div>
 
@@ -2432,7 +2432,7 @@
 <table class="table table-hover" style="width: auto !important; margin-left: auto; margin-right: auto;">
 <thead>
 <tr>
-<th style="border-bottom:hidden">
+<th style="border-bottom:hidden" colspan="1">
 </th>
 <th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="2">
 <div style="border-bottom: 1px solid #ddd; padding-bottom: 5px;">
@@ -2564,7 +2564,7 @@
 <table class="table table-striped" style="margin-left: auto; margin-right: auto;">
 <thead>
 <tr>
-<th style="border-bottom:hidden">
+<th style="border-bottom:hidden" colspan="1">
 </th>
 <th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="2">
 <div style="border-bottom: 1px solid #ddd; padding-bottom: 5px;">
@@ -2732,7 +2732,7 @@
 <table class="table table-striped table-bordered" style="margin-left: auto; margin-right: auto;">
 <thead>
 <tr>
-<th style="border-bottom:hidden">
+<th style="border-bottom:hidden" colspan="1">
 </th>
 <th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="6">
 <div style="border-bottom: 1px solid #ddd; padding-bottom: 5px;">
@@ -2741,7 +2741,7 @@
 </th>
 </tr>
 <tr>
-<th style="border-bottom:hidden">
+<th style="border-bottom:hidden" colspan="1">
 </th>
 <th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="4">
 <div style="border-bottom: 1px solid #ddd; padding-bottom: 5px;">
@@ -2755,7 +2755,7 @@
 </th>
 </tr>
 <tr>
-<th style="border-bottom:hidden">
+<th style="border-bottom:hidden" colspan="1">
 </th>
 <th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="2">
 <div style="border-bottom: 1px solid #ddd; padding-bottom: 5px;">
@@ -3549,7 +3549,7 @@
 2
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -3600,7 +3600,7 @@
 8
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3608,7 +3608,7 @@
 9
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -3616,7 +3616,7 @@
 10
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3630,7 +3630,7 @@
 11
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -3657,7 +3657,7 @@
 14
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -4182,7 +4182,7 @@
 </caption>
 <thead>
 <tr>
-<th style="border-bottom:hidden">
+<th style="border-bottom:hidden" colspan="1">
 </th>
 <th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="3">
 <div style="border-bottom: 1px solid #ddd; padding-bottom: 5px;">