diff --git a/addons/web/static/src/css/base.css b/addons/web/static/src/css/base.css
index 3f0e5a521ee..61809f2ef7c 100644
--- a/addons/web/static/src/css/base.css
+++ b/addons/web/static/src/css/base.css
@@ -68,10 +68,13 @@
   background-color: #f0f0f0;
 }
 .openerp thead th {
-  border-right: 1px dotted #afafb6;
+  border-left: 1px solid #dfdfdf;
 }
-.openerp thead th:last-child {
-  border-right: none;
+.openerp thead th:first-child {
+  border-left: none;
+}
+.openerp thead th.null {
+  border-left: none;
 }
 .openerp th, .openerp td {
   padding: 0;
diff --git a/addons/web/static/src/css/base.sass b/addons/web/static/src/css/base.sass
index d6e8802040b..41b75bec5c3 100644
--- a/addons/web/static/src/css/base.sass
+++ b/addons/web/static/src/css/base.sass
@@ -180,9 +180,11 @@ $sheet-max-width: 860px
         font-weight: bold
         background-color: #f0f0f0
         th
-            border-right: 1px dotted $tag-border
-            &:last-child
-                border-right: none
+            border-left: 1px solid #dfdfdf
+            &:first-child
+                border-left: none
+            &.null
+                border-left: none
     th, td
         padding: 0
         text-align: left