diff --git a/demo/index.js b/demo/index.js
index aa629fc..f8dbb3c 100644
--- a/demo/index.js
+++ b/demo/index.js
@@ -117,14 +117,21 @@ class ComponentChild extends React.Component {
 class App extends React.Component {
   state = {
     arrow: false,
+    customClass: ''
   }
 
   toggleArrow = () => {
     this.setState(state => ({
-      arrow: !state.arrow,
+      arrow: !state.arrow
     }))
   }
 
+  updateCustomClass = (e) => {
+    this.setState({
+      customClass: e.target.value
+    })
+  }
+
   render() {
     return (
       <main className="container">
@@ -165,6 +172,12 @@ class App extends React.Component {
             </Tippy>
           </Tippy>
         </Tippy>
+
+        <h1>Other</h1>
+        <input type="text" placeholder="Enter class" onChange={this.updateCustomClass}/>
+        <Tippy placement="bottom" className={this.state.customClass}>
+          <button>Custom class</button>
+        </Tippy>
       </main>
     )
   }
diff --git a/index.d.ts b/index.d.ts
index c9ad244..0358537 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -9,6 +9,7 @@ export interface TippyProps extends Omit<Props, 'content'> {
   onCreate?: (tip: Instance) => void
   isVisible?: boolean
   isEnabled?: boolean
+  className?: string
 }
 
 declare const Tippy: React.ForwardRefExoticComponent<TippyProps>
diff --git a/src/Tippy.js b/src/Tippy.js
index 8ae580d..41c88f2 100644
--- a/src/Tippy.js
+++ b/src/Tippy.js
@@ -4,6 +4,7 @@ import React, {
   useState,
   useRef,
   useEffect,
+  useLayoutEffect,
 } from 'react'
 import { createPortal } from 'react-dom'
 import PropTypes from 'prop-types'
@@ -13,6 +14,7 @@ import {
   hasOwnProperty,
   ssrSafeCreateDiv,
   preserveRef,
+  updateClassName,
 } from './utils'
 
 function Tippy(props) {
@@ -33,12 +35,17 @@ function Tippy(props) {
   useEffect(() => {
     instanceRef.current = tippy(targetRef.current, options)
 
-    const { onCreate, isEnabled, isVisible } = props
+    const { onCreate, isEnabled, isVisible, className } = props
 
     if (onCreate) {
       onCreate(instanceRef.current)
     }
 
+    if (className) {
+      const { tooltip } = instanceRef.current.popperChildren
+      updateClassName(tooltip, 'add', props.className)
+    }
+
     if (isEnabled === false) {
       instanceRef.current.disable()
     }
@@ -55,7 +62,7 @@ function Tippy(props) {
     }
   }, [])
 
-  useEffect(() => {
+  useLayoutEffect(() => {
     if (!isMounted) {
       return
     }
@@ -70,7 +77,6 @@ function Tippy(props) {
     if (isEnabled === false) {
       instanceRef.current.disable()
     }
-
     if (isVisible === true) {
       instanceRef.current.show()
     }
@@ -79,6 +85,19 @@ function Tippy(props) {
     }
   })
 
+  useLayoutEffect(() => {
+    if (!isMounted) {
+      return
+    }
+
+    const { tooltip } = instanceRef.current.popperChildren
+    updateClassName(tooltip, 'add', props.className)
+
+    return () => {
+      updateClassName(tooltip, 'remove', props.className)
+    }
+  }, [props.className])
+
   return (
     <>
       {cloneElement(props.children, {
@@ -99,6 +118,7 @@ Tippy.propTypes = {
   onCreate: PropTypes.func,
   isVisible: PropTypes.bool,
   isEnabled: PropTypes.bool,
+  className: PropTypes.string,
 }
 
 Tippy.defaultProps = {
diff --git a/src/utils.js b/src/utils.js
index 2f531db..22d8818 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -1,6 +1,6 @@
 export function getNativeTippyProps(props) {
   // eslint-disable-next-line no-unused-vars
-  const { children, onCreate, isVisible, isEnabled, ...nativeProps } = props
+  const { children, onCreate, isVisible, isEnabled, className, ...nativeProps } = props
   return nativeProps
 }
 
@@ -22,3 +22,11 @@ export function preserveRef(ref, node) {
 export function ssrSafeCreateDiv() {
   return typeof document !== 'undefined' && document.createElement('div')
 }
+
+export function updateClassName(tooltip, action, classNames) {
+  classNames.split(/\s+/).forEach(name => {
+    if (name) {
+      tooltip.classList[action](name)
+    }
+  })
+}
diff --git a/test/Tippy.test.js b/test/Tippy.test.js
index 8d276f1..70b12f2 100644
--- a/test/Tippy.test.js
+++ b/test/Tippy.test.js
@@ -53,6 +53,29 @@ describe('<Tippy />', () => {
     expect(tip.popper.querySelector('strong')).not.toBeNull()
   })
 
+  test('custom class name get added to DOM', () => {
+    const className = 'hello'
+    const { container } = render(
+      <Tippy content="tip content" className={className}>
+        <button />
+      </Tippy>,
+    )
+    const tip = container.querySelector('button')._tippy
+    expect(tip.popper.querySelector(`.${className}`)).not.toBeNull()
+  })
+
+  test('custom class name get added to DOM', () => {
+    const classNames = 'hello world'
+    const { container } = render(
+      <Tippy content="tip content" className={classNames}>
+        <button />
+      </Tippy>,
+    )
+    const tip = container.querySelector('button')._tippy
+    expect(tip.popper.querySelector('.hello')).not.toBeNull()
+    expect(tip.popper.querySelector('.world')).not.toBeNull()
+  })
+
   test('unmount destroys the tippy instance and allows garbage collection', () => {
     const { container, unmount } = render(
       <Tippy content="tooltip">