diff --git a/packages/virtualdom/src/index.ts b/packages/virtualdom/src/index.ts
index 43a5bb37b..e077596fa 100644
--- a/packages/virtualdom/src/index.ts
+++ b/packages/virtualdom/src/index.ts
@@ -10,6 +10,115 @@ import {
 } from '@phosphor/algorithm';
 
 
+/**
+ * Define global element types to JSX namespace.
+ */
+declare global {
+  namespace JSX {
+    interface IntrinsicElements {
+      a: ElementAttrs;
+      abbr: ElementAttrs;
+      address: ElementAttrs;
+      area: ElementAttrs;
+      article: ElementAttrs;
+      aside: ElementAttrs;
+      audio: ElementAttrs;
+      b: ElementAttrs;
+      bdi: ElementAttrs;
+      bdo: ElementAttrs;
+      blockquote: ElementAttrs;
+      br: ElementAttrs;
+      button: ElementAttrs;
+      canvas: ElementAttrs;
+      caption: ElementAttrs;
+      cite: ElementAttrs;
+      code: ElementAttrs;
+      col: ElementAttrs;
+      colgroup: ElementAttrs;
+      data: ElementAttrs;
+      datalist: ElementAttrs;
+      dd: ElementAttrs;
+      del: ElementAttrs;
+      dfn: ElementAttrs;
+      div: ElementAttrs;
+      dl: ElementAttrs;
+      dt: ElementAttrs;
+      em: ElementAttrs;
+      embed: ElementAttrs;
+      fieldset: ElementAttrs;
+      figcaption: ElementAttrs;
+      figure: ElementAttrs;
+      footer: ElementAttrs;
+      form: ElementAttrs;
+      h1: ElementAttrs;
+      h2: ElementAttrs;
+      h3: ElementAttrs;
+      h4: ElementAttrs;
+      h5: ElementAttrs;
+      h6: ElementAttrs;
+      header: ElementAttrs;
+      hr: ElementAttrs;
+      i: ElementAttrs;
+      iframe: ElementAttrs;
+      img: ElementAttrs;
+      input: ElementAttrs;
+      ins: ElementAttrs;
+      kbd: ElementAttrs;
+      label: ElementAttrs;
+      legend: ElementAttrs;
+      li: ElementAttrs;
+      main: ElementAttrs;
+      map: ElementAttrs;
+      mark: ElementAttrs;
+      meter: ElementAttrs;
+      nav: ElementAttrs;
+      noscript: ElementAttrs;
+      object: ElementAttrs;
+      ol: ElementAttrs;
+      optgroup: ElementAttrs;
+      option: ElementAttrs;
+      output: ElementAttrs;
+      p: ElementAttrs;
+      param: ElementAttrs;
+      pre: ElementAttrs;
+      progress: ElementAttrs;
+      q: ElementAttrs;
+      rp: ElementAttrs;
+      rt: ElementAttrs;
+      ruby: ElementAttrs;
+      s: ElementAttrs;
+      samp: ElementAttrs;
+      section: ElementAttrs;
+      select: ElementAttrs;
+      small: ElementAttrs;
+      source: ElementAttrs;
+      span: ElementAttrs;
+      strong: ElementAttrs;
+      sub: ElementAttrs;
+      summary: ElementAttrs;
+      sup: ElementAttrs;
+      table: ElementAttrs;
+      tbody: ElementAttrs;
+      td: ElementAttrs;
+      textarea: ElementAttrs;
+      tfoot: ElementAttrs;
+      th: ElementAttrs;
+      thead: ElementAttrs;
+      time: ElementAttrs;
+      title: ElementAttrs;
+      tr: ElementAttrs;
+      track: ElementAttrs;
+      u: ElementAttrs;
+      ul: ElementAttrs;
+      var_: ElementAttrs;
+      video: ElementAttrs;
+      wbr: ElementAttrs;
+    }
+    interface Element extends VirtualElement { }
+  }
+}
+
+
 /**
  * The names of the supported HTML5 DOM element attributes.
  *
@@ -649,6 +758,11 @@ type ElementSpecialAttrs = {
    * The inline style for the rendered DOM element.
    */
   readonly style?: ElementInlineStyle;
+  
+  /**
+   * The children attribute for functional custom elements.
+   */
+  children?: ReadonlyArray<VirtualNode>;
 };
 
 
@@ -1020,6 +1134,12 @@ namespace Private {
     if (node.type === 'text') {
       return document.createTextNode(node.content);
     }
+    
+    // If node is a function, call if with its attrs to return a VirtualNode.
+    if (typeof node.tag === 'function') {
+      node.attrs.children = node.children;
+      node = node.tag(node.attrs) as VirtualElement;
+    }
 
     // Create the HTML element with the specified tag.
     let element = document.createElement(node.tag);