diff --git a/core/modules/filter/filter.filter_html.admin.js b/core/modules/filter/filter.filter_html.admin.js
index d05402b5bc..5221fafe06 100644
--- a/core/modules/filter/filter.filter_html.admin.js
+++ b/core/modules/filter/filter.filter_html.admin.js
@@ -243,12 +243,12 @@
         // Let the browser do the parsing work for us.
         currentTag = allowedTags[t];
         // Table tags need to be wrapped in a <table>.
-        if (['<caption>', '<tbody>', '<thead>', '<tfoot>', '<th>', '<td>', '<tr>'].indexOf(currentTag) == -1) {
+        if (['<caption>', '<tbody>', '<thead>', '<tfoot>', '<th>', '<td>', '<tr>'].indexOf(currentTag) === -1) {
           sandbox.innerHTML = currentTag;
           node = sandbox.firstChild;
         }
         else {
-          sandbox.innerHTML = "<table>" + currentTag;
+          sandbox.innerHTML = '<table>' + currentTag;
           switch (currentTag) {
             case '<th>':
             case '<td>':