diff --git a/.prettierrc b/.prettierrc
new file mode 100644
index 00000000..544138be
--- /dev/null
+++ b/.prettierrc
@@ -0,0 +1,3 @@
+{
+  "singleQuote": true
+}
diff --git a/packages/react-json-tree/.eslintignore b/packages/react-json-tree/.eslintignore
new file mode 100644
index 00000000..a65b4177
--- /dev/null
+++ b/packages/react-json-tree/.eslintignore
@@ -0,0 +1 @@
+lib
diff --git a/packages/react-json-tree/package.json b/packages/react-json-tree/package.json
index bbdd6602..ba6b2d80 100644
--- a/packages/react-json-tree/package.json
+++ b/packages/react-json-tree/package.json
@@ -12,6 +12,8 @@
     "build:js": "babel src --out-dir lib --extensions \".ts,.tsx\" --source-maps inline",
     "build:umd": "rimraf ./umd && webpack --progress --config webpack.config.umd.js",
     "build:umd:min": "webpack --env.minimize --progress --config webpack.config.umd.js",
+    "lint": "eslint . --ext .ts,.tsx",
+    "lint:fix": "eslint . --ext .ts,.tsx --fix",
     "test": "jest",
     "prepare": "npm run build",
     "prepublishOnly": "npm run test && npm run clean && npm run build && npm run build:umd && npm run build:umd:min",
@@ -49,11 +51,12 @@
     "@babel/preset-env": "^7.3.1",
     "@babel/preset-react": "^7.0.0",
     "@babel/preset-typescript": "^7.9.0",
+    "@types/react": "^15.0.0 || ^16.0.0",
     "@typescript-eslint/eslint-plugin": "^2.31.0",
     "@typescript-eslint/parser": "^2.31.0",
     "babel-loader": "^8.0.5",
     "jest": "^24.1.0",
-    "react": "^16.0.0",
+    "react": "^15.0.0 || ^16.0.0",
     "react-dom": "^16.0.0",
     "react-test-renderer": "^16.0.0",
     "rimraf": "^2.5.2",
diff --git a/packages/react-json-tree/src/ItemRange.tsx b/packages/react-json-tree/src/ItemRange.tsx
index f7ed29a8..14d1cf8e 100644
--- a/packages/react-json-tree/src/ItemRange.tsx
+++ b/packages/react-json-tree/src/ItemRange.tsx
@@ -1,8 +1,21 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import JSONArrow from './JSONArrow';
+import { CircularPropsPassedThroughItemRange } from './types';
 
-export default class ItemRange extends React.Component {
+interface Props extends CircularPropsPassedThroughItemRange {
+  data: any;
+  nodeType: string;
+  from: number;
+  to: number;
+  renderChildNodes: (props: Props, from: number, to: number) => React.ReactNode;
+}
+
+interface State {
+  expanded: boolean;
+}
+
+export default class ItemRange extends React.Component<Props, State> {
   static propTypes = {
     styling: PropTypes.func.isRequired,
     from: PropTypes.number.isRequired,
@@ -11,7 +24,7 @@ export default class ItemRange extends React.Component {
     nodeType: PropTypes.string.isRequired
   };
 
-  constructor(props) {
+  constructor(props: Props) {
     super(props);
     this.state = { expanded: false };
 
@@ -42,7 +55,7 @@ export default class ItemRange extends React.Component {
     );
   }
 
-  handleClick() {
+  handleClick = () => {
     this.setState({ expanded: !this.state.expanded });
-  }
+  };
 }
diff --git a/packages/react-json-tree/src/JSONArrayNode.tsx b/packages/react-json-tree/src/JSONArrayNode.tsx
index 98a95b84..66a9552f 100644
--- a/packages/react-json-tree/src/JSONArrayNode.tsx
+++ b/packages/react-json-tree/src/JSONArrayNode.tsx
@@ -1,15 +1,21 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import JSONNestedNode from './JSONNestedNode';
+import { CircularPropsPassedThroughJSONNode } from './types';
 
 // Returns the "n Items" string for this node,
 // generating and caching it if it hasn't been created yet.
-function createItemString(data) {
+function createItemString(data: any) {
   return `${data.length} ${data.length !== 1 ? 'items' : 'item'}`;
 }
 
+interface Props extends CircularPropsPassedThroughJSONNode {
+  data: any;
+  nodeType: string;
+}
+
 // Configures <JSONNestedNode> to render an Array
-const JSONArrayNode = ({ data, ...props }) => (
+const JSONArrayNode: React.FunctionComponent<Props> = ({ data, ...props }) => (
   <JSONNestedNode
     {...props}
     data={data}
diff --git a/packages/react-json-tree/src/JSONArrow.tsx b/packages/react-json-tree/src/JSONArrow.tsx
index 138374e0..be199c3d 100644
--- a/packages/react-json-tree/src/JSONArrow.tsx
+++ b/packages/react-json-tree/src/JSONArrow.tsx
@@ -1,7 +1,22 @@
 import React from 'react';
 import PropTypes from 'prop-types';
+import { StylingFunction } from 'react-base16-styling';
 
-const JSONArrow = ({ styling, arrowStyle, expanded, nodeType, onClick }) => (
+interface Props {
+  styling: StylingFunction;
+  arrowStyle?: 'single' | 'double';
+  expanded: boolean;
+  nodeType: string;
+  onClick: React.MouseEventHandler<HTMLDivElement>;
+}
+
+const JSONArrow: React.FunctionComponent<Props> = ({
+  styling,
+  arrowStyle,
+  expanded,
+  nodeType,
+  onClick
+}) => (
   <div {...styling('arrowContainer', arrowStyle)} onClick={onClick}>
     <div {...styling(['arrow', 'arrowSign'], nodeType, expanded, arrowStyle)}>
       {'\u25B6'}
diff --git a/packages/react-json-tree/src/JSONIterableNode.tsx b/packages/react-json-tree/src/JSONIterableNode.tsx
index f252481c..dff51ad5 100644
--- a/packages/react-json-tree/src/JSONIterableNode.tsx
+++ b/packages/react-json-tree/src/JSONIterableNode.tsx
@@ -1,9 +1,10 @@
 import React from 'react';
 import JSONNestedNode from './JSONNestedNode';
+import { CircularPropsPassedThroughJSONNode } from './types';
 
 // Returns the "n Items" string for this node,
 // generating and caching it if it hasn't been created yet.
-function createItemString(data, limit) {
+function createItemString(data: any, limit: number) {
   let count = 0;
   let hasMore = false;
   if (Number.isSafeInteger(data.size)) {
@@ -21,8 +22,13 @@ function createItemString(data, limit) {
   return `${hasMore ? '>' : ''}${count} ${count !== 1 ? 'entries' : 'entry'}`;
 }
 
+interface Props extends CircularPropsPassedThroughJSONNode {
+  data: any;
+  nodeType: string;
+}
+
 // Configures <JSONNestedNode> to render an iterable
-export default function JSONIterableNode({ ...props }) {
+const JSONIterableNode: React.FunctionComponent<Props> = ({ ...props }) => {
   return (
     <JSONNestedNode
       {...props}
@@ -31,4 +37,6 @@ export default function JSONIterableNode({ ...props }) {
       createItemString={createItemString}
     />
   );
-}
+};
+
+export default JSONIterableNode;
diff --git a/packages/react-json-tree/src/JSONNestedNode.tsx b/packages/react-json-tree/src/JSONNestedNode.tsx
index 2c3afcac..3e62815c 100644
--- a/packages/react-json-tree/src/JSONNestedNode.tsx
+++ b/packages/react-json-tree/src/JSONNestedNode.tsx
@@ -4,12 +4,40 @@ import JSONArrow from './JSONArrow';
 import getCollectionEntries from './getCollectionEntries';
 import JSONNode from './JSONNode';
 import ItemRange from './ItemRange';
+import {
+  CircularPropsPassedThroughJSONNestedNode,
+  CircularPropsPassedThroughRenderChildNodes
+} from './types';
 
 /**
  * Renders nested values (eg. objects, arrays, lists, etc.)
  */
 
-function renderChildNodes(props, from, to) {
+export interface RenderChildNodesProps
+  extends CircularPropsPassedThroughRenderChildNodes {
+  data: any;
+  nodeType: string;
+}
+
+interface Range {
+  from: number;
+  to: number;
+}
+
+interface Entry {
+  key: string | number;
+  value: any;
+}
+
+function isRange(rangeOrEntry: Range | Entry): rangeOrEntry is Range {
+  return (rangeOrEntry as Range).to !== undefined;
+}
+
+function renderChildNodes(
+  props: RenderChildNodesProps,
+  from?: number,
+  to?: number
+) {
   const {
     nodeType,
     data,
@@ -19,7 +47,7 @@ function renderChildNodes(props, from, to) {
     postprocessValue,
     sortObjectKeys
   } = props;
-  const childNodes = [];
+  const childNodes: React.ReactNode[] = [];
 
   getCollectionEntries(
     nodeType,
@@ -29,7 +57,7 @@ function renderChildNodes(props, from, to) {
     from,
     to
   ).forEach(entry => {
-    if (entry.to) {
+    if (isRange(entry)) {
       childNodes.push(
         <ItemRange
           {...props}
@@ -41,9 +69,9 @@ function renderChildNodes(props, from, to) {
       );
     } else {
       const { key, value } = entry;
-      const isCircular = circularCache.indexOf(value) !== -1;
+      const isCircular = circularCache.includes(value);
 
-      const node = (
+      childNodes.push(
         <JSONNode
           {...props}
           {...{ postprocessValue, collectionLimit }}
@@ -55,17 +83,25 @@ function renderChildNodes(props, from, to) {
           hideRoot={false}
         />
       );
-
-      if (node !== false) {
-        childNodes.push(node);
-      }
     }
   });
 
   return childNodes;
 }
 
-function getStateFromProps(props) {
+interface Props extends CircularPropsPassedThroughJSONNestedNode {
+  data: any;
+  nodeType: string;
+  nodeTypeIndicator: string;
+  createItemString: (data: any, collectionLimit: number) => string;
+  expandable: boolean;
+}
+
+interface State {
+  expanded: boolean;
+}
+
+function getStateFromProps(props: Props) {
   // calculate individual node expansion if necessary
   const expanded =
     props.shouldExpandNode && !props.isCircular
@@ -76,7 +112,7 @@ function getStateFromProps(props) {
   };
 }
 
-export default class JSONNestedNode extends React.Component {
+export default class JSONNestedNode extends React.Component<Props, State> {
   static propTypes = {
     getItemString: PropTypes.func.isRequired,
     nodeTypeIndicator: PropTypes.any,
@@ -104,26 +140,26 @@ export default class JSONNestedNode extends React.Component {
     expandable: true
   };
 
-  constructor(props) {
+  constructor(props: Props) {
     super(props);
     this.state = getStateFromProps(props);
   }
 
-  UNSAFE_componentWillReceiveProps(nextProps) {
+  UNSAFE_componentWillReceiveProps(nextProps: Props) {
     const nextState = getStateFromProps(nextProps);
     if (getStateFromProps(this.props).expanded !== nextState.expanded) {
       this.setState(nextState);
     }
   }
 
-  shouldComponentUpdate(nextProps, nextState) {
+  shouldComponentUpdate(nextProps: Props, nextState: State) {
     return (
       !!Object.keys(nextProps).find(
         key =>
           key !== 'circularCache' &&
           (key === 'keyPath'
             ? nextProps[key].join('/') !== this.props[key].join('/')
-            : nextProps[key] !== this.props[key])
+            : nextProps[key as keyof Props] !== this.props[key as keyof Props])
       ) || nextState.expanded !== this.state.expanded
     );
   }
@@ -159,7 +195,7 @@ export default class JSONNestedNode extends React.Component {
       itemType,
       createItemString(data, collectionLimit)
     );
-    const stylingArgs = [keyPath, nodeType, expanded, expandable];
+    const stylingArgs = [keyPath, nodeType, expanded, expandable] as const;
 
     return hideRoot ? (
       <li {...styling('rootNode', ...stylingArgs)}>
diff --git a/packages/react-json-tree/src/JSONNode.tsx b/packages/react-json-tree/src/JSONNode.tsx
index bc7a3f1a..771f987f 100644
--- a/packages/react-json-tree/src/JSONNode.tsx
+++ b/packages/react-json-tree/src/JSONNode.tsx
@@ -5,8 +5,15 @@ import JSONObjectNode from './JSONObjectNode';
 import JSONArrayNode from './JSONArrayNode';
 import JSONIterableNode from './JSONIterableNode';
 import JSONValueNode from './JSONValueNode';
+import { CircularPropsPassedThroughJSONNode } from './types';
 
-const JSONNode = ({
+interface Props extends CircularPropsPassedThroughJSONNode {
+  keyPath: (string | number)[];
+  value: any;
+  isCustomNode: (value: any) => boolean;
+}
+
+const JSONNode: React.FunctionComponent<Props> = ({
   getItemString,
   keyPath,
   labelRenderer,
@@ -97,7 +104,7 @@ const JSONNode = ({
 JSONNode.propTypes = {
   getItemString: PropTypes.func.isRequired,
   keyPath: PropTypes.arrayOf(
-    PropTypes.oneOfType([PropTypes.string, PropTypes.number])
+    PropTypes.oneOfType([PropTypes.string, PropTypes.number]).isRequired
   ).isRequired,
   labelRenderer: PropTypes.func.isRequired,
   styling: PropTypes.func.isRequired,
diff --git a/packages/react-json-tree/src/JSONObjectNode.tsx b/packages/react-json-tree/src/JSONObjectNode.tsx
index a8e55827..2e34853a 100644
--- a/packages/react-json-tree/src/JSONObjectNode.tsx
+++ b/packages/react-json-tree/src/JSONObjectNode.tsx
@@ -1,16 +1,22 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import JSONNestedNode from './JSONNestedNode';
+import { CircularPropsPassedThroughJSONNode } from './types';
 
 // Returns the "n Items" string for this node,
 // generating and caching it if it hasn't been created yet.
-function createItemString(data) {
+function createItemString(data: any) {
   const len = Object.getOwnPropertyNames(data).length;
   return `${len} ${len !== 1 ? 'keys' : 'key'}`;
 }
 
+interface Props extends CircularPropsPassedThroughJSONNode {
+  data: any;
+  nodeType: string;
+}
+
 // Configures <JSONNestedNode> to render an Object
-const JSONObjectNode = ({ data, ...props }) => (
+const JSONObjectNode: React.FunctionComponent<Props> = ({ data, ...props }) => (
   <JSONNestedNode
     {...props}
     data={data}
@@ -23,7 +29,7 @@ const JSONObjectNode = ({ data, ...props }) => (
 
 JSONObjectNode.propTypes = {
   data: PropTypes.object,
-  nodeType: PropTypes.string
+  nodeType: PropTypes.string.isRequired
 };
 
 export default JSONObjectNode;
diff --git a/packages/react-json-tree/src/JSONValueNode.tsx b/packages/react-json-tree/src/JSONValueNode.tsx
index 1dd7e93b..2d47cb15 100644
--- a/packages/react-json-tree/src/JSONValueNode.tsx
+++ b/packages/react-json-tree/src/JSONValueNode.tsx
@@ -1,18 +1,25 @@
 import React from 'react';
 import PropTypes from 'prop-types';
+import { JSONValueNodeCircularPropsProvidedByJSONNode } from './types';
 
 /**
  * Renders simple values (eg. strings, numbers, booleans, etc)
  */
 
-const JSONValueNode = ({
+interface Props extends JSONValueNodeCircularPropsProvidedByJSONNode {
+  nodeType: string;
+  value: any;
+  valueGetter?: (value: any) => any;
+}
+
+const JSONValueNode: React.FunctionComponent<Props> = ({
   nodeType,
   styling,
   labelRenderer,
   keyPath,
   valueRenderer,
   value,
-  valueGetter
+  valueGetter = value => value
 }) => (
   <li {...styling('value', nodeType, keyPath)}>
     <label {...styling(['label', 'valueLabel'], nodeType, keyPath)}>
@@ -29,15 +36,11 @@ JSONValueNode.propTypes = {
   styling: PropTypes.func.isRequired,
   labelRenderer: PropTypes.func.isRequired,
   keyPath: PropTypes.arrayOf(
-    PropTypes.oneOfType([PropTypes.string, PropTypes.number])
+    PropTypes.oneOfType([PropTypes.string, PropTypes.number]).isRequired
   ).isRequired,
   valueRenderer: PropTypes.func.isRequired,
   value: PropTypes.any,
   valueGetter: PropTypes.func
 };
 
-JSONValueNode.defaultProps = {
-  valueGetter: value => value
-};
-
 export default JSONValueNode;
diff --git a/packages/react-json-tree/src/createStylingFromTheme.ts b/packages/react-json-tree/src/createStylingFromTheme.ts
index deb86ff4..bad6c456 100644
--- a/packages/react-json-tree/src/createStylingFromTheme.ts
+++ b/packages/react-json-tree/src/createStylingFromTheme.ts
@@ -1,7 +1,11 @@
-import { createStyling } from 'react-base16-styling';
+import {
+  createStyling,
+  Base16Theme,
+  StylingConfig
+} from 'react-base16-styling';
 import solarized from './themes/solarized';
 
-const colorMap = theme => ({
+const colorMap = (theme: Base16Theme) => ({
   BACKGROUND_COLOR: theme.base00,
   TEXT_COLOR: theme.base07,
   STRING_COLOR: theme.base0B,
@@ -18,7 +22,12 @@ const colorMap = theme => ({
   ITEM_STRING_EXPANDED_COLOR: theme.base03
 });
 
-const valueColorMap = colors => ({
+type Color = keyof ReturnType<typeof colorMap>;
+type Colors = {
+  [color in Color]: string;
+};
+
+const valueColorMap = (colors: Colors) => ({
   String: colors.STRING_COLOR,
   Date: colors.DATE_COLOR,
   Number: colors.NUMBER_COLOR,
@@ -29,7 +38,7 @@ const valueColorMap = colors => ({
   Symbol: colors.SYMBOL_COLOR
 });
 
-const getDefaultThemeStyling = theme => {
+const getDefaultThemeStyling = (theme: Base16Theme): StylingConfig => {
   const colors = colorMap(theme);
 
   return {
@@ -73,7 +82,9 @@ const getDefaultThemeStyling = theme => {
     valueText: ({ style }, nodeType) => ({
       style: {
         ...style,
-        color: valueColorMap(colors)[nodeType]
+        color: valueColorMap(colors)[
+          nodeType as keyof ReturnType<typeof valueColorMap>
+        ]
       }
     }),
 
diff --git a/packages/react-json-tree/src/getCollectionEntries.ts b/packages/react-json-tree/src/getCollectionEntries.ts
index 2579bbe8..b255b850 100644
--- a/packages/react-json-tree/src/getCollectionEntries.ts
+++ b/packages/react-json-tree/src/getCollectionEntries.ts
@@ -1,4 +1,4 @@
-function getLength(type, collection) {
+function getLength(type: string, collection: any) {
   if (type === 'Object') {
     return Object.keys(collection).length;
   } else if (type === 'Array') {
@@ -8,11 +8,17 @@ function getLength(type, collection) {
   return Infinity;
 }
 
-function isIterableMap(collection) {
+function isIterableMap(collection: any) {
   return typeof collection.set === 'function';
 }
 
-function getEntries(type, collection, sortObjectKeys, from = 0, to = Infinity) {
+function getEntries(
+  type: string,
+  collection: any,
+  sortObjectKeys?: ((a: any, b: any) => number) | boolean | undefined,
+  from = 0,
+  to = Infinity
+): { entries: { key: string | number; value: any }[]; hasMore?: boolean } {
   let res;
 
   if (type === 'Object') {
@@ -31,7 +37,7 @@ function getEntries(type, collection, sortObjectKeys, from = 0, to = Infinity) {
     res = {
       entries: collection
         .slice(from, to + 1)
-        .map((val, idx) => ({ key: idx + from, value: val }))
+        .map((val: any, idx: number) => ({ key: idx + from, value: val }))
     };
   } else {
     let idx = 0;
@@ -74,7 +80,7 @@ function getEntries(type, collection, sortObjectKeys, from = 0, to = Infinity) {
   return res;
 }
 
-function getRanges(from, to, limit) {
+function getRanges(from: number, to: number, limit: number) {
   const ranges = [];
   while (to - from > limit * limit) {
     limit = limit * limit;
@@ -87,10 +93,10 @@ function getRanges(from, to, limit) {
 }
 
 export default function getCollectionEntries(
-  type,
-  collection,
-  sortObjectKeys,
-  limit,
+  type: string,
+  collection: any,
+  sortObjectKeys: ((a: any, b: any) => number) | boolean | undefined,
+  limit: number,
   from = 0,
   to = Infinity
 ) {
diff --git a/packages/react-json-tree/src/index.tsx b/packages/react-json-tree/src/index.tsx
index e7504eb7..2eaf73e1 100644
--- a/packages/react-json-tree/src/index.tsx
+++ b/packages/react-json-tree/src/index.tsx
@@ -7,19 +7,47 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import JSONNode from './JSONNode';
 import createStylingFromTheme from './createStylingFromTheme';
-import { invertTheme } from 'react-base16-styling';
+import {
+  Base16Theme,
+  invertTheme,
+  StylingConfig,
+  StylingFunction,
+  Theme
+} from 'react-base16-styling';
+import { CircularPropsPassedThroughJSONTree } from './types';
 
-const identity = value => value;
-const expandRootNode = (keyName, data, level) => level === 0;
-const defaultItemString = (type, data, itemType, itemString) => (
+interface Props extends CircularPropsPassedThroughJSONTree {
+  theme: Theme;
+  invertTheme: boolean;
+  data: any;
+}
+
+interface State {
+  styling: StylingFunction;
+}
+
+const identity = (value: any) => value;
+const expandRootNode = (
+  keyPath: (string | number)[],
+  data: any,
+  level: number
+) => level === 0;
+const defaultItemString = (
+  type: string,
+  data: any,
+  itemType: React.ReactNode,
+  itemString: string
+) => (
   <span>
     {itemType} {itemString}
   </span>
 );
-const defaultLabelRenderer = ([label]) => <span>{label}:</span>;
+const defaultLabelRenderer = ([label]: (string | number)[]) => (
+  <span>{label}:</span>
+);
 const noCustomNode = () => false;
 
-function checkLegacyTheming(theme, props) {
+function checkLegacyTheming(theme: Theme, props: Props) {
   const deprecatedStylingMethodsMap = {
     getArrowStyle: 'arrow',
     getListStyle: 'nestedNodeChildren',
@@ -30,7 +58,7 @@ function checkLegacyTheming(theme, props) {
 
   const deprecatedStylingMethods = Object.keys(
     deprecatedStylingMethodsMap
-  ).filter(name => props[name]);
+  ).filter(name => props[name as keyof Props]);
 
   if (deprecatedStylingMethods.length > 0) {
     if (typeof theme === 'string') {
@@ -47,10 +75,14 @@ function checkLegacyTheming(theme, props) {
         `Styling method "${name}" is deprecated, use "theme" property instead`
       );
 
-      theme[deprecatedStylingMethodsMap[name]] = ({ style }, ...args) => ({
+      (theme as StylingConfig)[
+        deprecatedStylingMethodsMap[
+          name as keyof typeof deprecatedStylingMethodsMap
+        ]
+      ] = ({ style }, ...args) => ({
         style: {
           ...style,
-          ...props[name](...args)
+          ...props[name as keyof Props](...args)
         }
       });
     });
@@ -59,19 +91,28 @@ function checkLegacyTheming(theme, props) {
   return theme;
 }
 
-function getStateFromProps(props) {
+function isStylingConfig(
+  themeOrStyling: Base16Theme | StylingConfig
+): themeOrStyling is StylingConfig {
+  return (themeOrStyling as StylingConfig).extend !== undefined;
+}
+
+function getStateFromProps(props: Props) {
   let theme = checkLegacyTheming(props.theme, props);
   if (props.invertTheme) {
     if (typeof theme === 'string') {
       theme = `${theme}:inverted`;
-    } else if (theme && theme.extend) {
-      if (typeof theme === 'string') {
+    } else if (theme && isStylingConfig(theme) && theme.extend) {
+      if (typeof theme.extend === 'string') {
         theme = { ...theme, extend: `${theme.extend}:inverted` };
       } else {
-        theme = { ...theme, extend: invertTheme(theme.extend) };
+        theme = {
+          ...theme,
+          extend: invertTheme(theme.extend)
+        } as StylingConfig;
       }
     } else if (theme) {
-      theme = invertTheme(theme);
+      theme = invertTheme(theme as Base16Theme);
     }
   }
   return {
@@ -79,7 +120,7 @@ function getStateFromProps(props) {
   };
 }
 
-export default class JSONTree extends React.Component {
+export default class JSONTree extends React.Component<Props, State> {
   static propTypes = {
     data: PropTypes.oneOfType([PropTypes.array, PropTypes.object]).isRequired,
     hideRoot: PropTypes.bool,
@@ -105,22 +146,26 @@ export default class JSONTree extends React.Component {
     invertTheme: true
   };
 
-  constructor(props) {
+  constructor(props: Props) {
     super(props);
     this.state = getStateFromProps(props);
   }
 
-  UNSAFE_componentWillReceiveProps(nextProps) {
-    if (['theme', 'invertTheme'].find(k => nextProps[k] !== this.props[k])) {
+  UNSAFE_componentWillReceiveProps(nextProps: Props) {
+    if (
+      ['theme', 'invertTheme'].find(
+        k => nextProps[k as keyof Props] !== this.props[k as keyof Props]
+      )
+    ) {
       this.setState(getStateFromProps(nextProps));
     }
   }
 
-  shouldComponentUpdate(nextProps) {
+  shouldComponentUpdate(nextProps: Props) {
     return !!Object.keys(nextProps).find(k =>
       k === 'keyPath'
         ? nextProps[k].join('/') !== this.props[k].join('/')
-        : nextProps[k] !== this.props[k]
+        : nextProps[k as keyof Props] !== this.props[k as keyof Props]
     );
   }
 
diff --git a/packages/react-json-tree/src/objType.ts b/packages/react-json-tree/src/objType.ts
index a43867fa..b3a6cc9a 100644
--- a/packages/react-json-tree/src/objType.ts
+++ b/packages/react-json-tree/src/objType.ts
@@ -1,4 +1,4 @@
-export default function objType(obj) {
+export default function objType(obj: any) {
   const type = Object.prototype.toString.call(obj).slice(8, -1);
   if (type === 'Object' && typeof obj[Symbol.iterator] === 'function') {
     return 'Iterable';
diff --git a/packages/react-json-tree/src/react-base16-styling.d.ts b/packages/react-json-tree/src/react-base16-styling.d.ts
new file mode 100644
index 00000000..aba85ae3
--- /dev/null
+++ b/packages/react-json-tree/src/react-base16-styling.d.ts
@@ -0,0 +1,52 @@
+declare module 'react-base16-styling' {
+  import React from 'react';
+
+  export interface Styling {
+    style?: React.CSSProperties;
+    className?: string;
+  }
+
+  export interface Base16Theme {
+    scheme?: string;
+    author?: string;
+    base00: string;
+    base01: string;
+    base02: string;
+    base03: string;
+    base04: string;
+    base05: string;
+    base06: string;
+    base07: string;
+    base08: string;
+    base09: string;
+    base0A: string;
+    base0B: string;
+    base0C: string;
+    base0D: string;
+    base0E: string;
+    base0F: string;
+  }
+
+  export type StylingValue =
+    | string
+    | React.CSSProperties
+    | ((styling: Styling, ...rest: any[]) => Styling);
+
+  export type StylingConfig = { [name: string]: StylingValue } & {
+    extend?: string | Base16Theme;
+  };
+
+  export type Theme = string | Base16Theme | StylingConfig;
+
+  export type StylingFunction = (
+    keys: string | Array<string | undefined | null>,
+    ...rest: any[]
+  ) => Styling;
+
+  export function invertTheme(base16Theme: Base16Theme): Base16Theme;
+
+  export function createStyling(
+    getDefaultStyling: (base16Theme: Base16Theme) => StylingConfig,
+    options?: { defaultBase16?: Theme; base16Themes?: Theme[] }
+  ): (theme: Theme, invertTheme?: boolean) => StylingFunction;
+}
diff --git a/packages/react-json-tree/src/types.ts b/packages/react-json-tree/src/types.ts
new file mode 100644
index 00000000..70cde159
--- /dev/null
+++ b/packages/react-json-tree/src/types.ts
@@ -0,0 +1,74 @@
+import React from 'react';
+import { StylingFunction } from 'react-base16-styling';
+
+interface SharedCircularPropsPassedThroughJSONTree {
+  keyPath: (string | number)[];
+  labelRenderer: (
+    keyPath: (string | number)[],
+    nodeType: string,
+    expanded: boolean,
+    expandable: boolean
+  ) => React.ReactNode;
+}
+interface SharedCircularPropsProvidedByJSONTree
+  extends SharedCircularPropsPassedThroughJSONTree {
+  styling: StylingFunction;
+}
+interface JSONValueNodeCircularPropsPassedThroughJSONTree {
+  valueRenderer: (
+    valueAsString: any,
+    value: any,
+    ...keyPath: (string | number)[]
+  ) => React.ReactNode;
+}
+export type JSONValueNodeCircularPropsProvidedByJSONNode = SharedCircularPropsProvidedByJSONTree &
+  JSONValueNodeCircularPropsPassedThroughJSONTree;
+
+interface JSONNestedNodeCircularPropsPassedThroughJSONTree {
+  shouldExpandNode: (
+    keyPath: (string | number)[],
+    data: any,
+    level: number
+  ) => boolean;
+  hideRoot: boolean;
+  getItemString: (
+    nodeType: string,
+    data: any,
+    itemType: React.ReactNode,
+    itemString: string
+  ) => React.ReactNode;
+  postprocessValue: (value: any) => any;
+  isCustomNode: (value: any) => boolean;
+  collectionLimit: number;
+  sortObjectKeys?: (a: any, b: any) => number | boolean;
+}
+export type CircularPropsPassedThroughJSONTree = SharedCircularPropsPassedThroughJSONTree &
+  JSONValueNodeCircularPropsPassedThroughJSONTree &
+  JSONNestedNodeCircularPropsPassedThroughJSONTree;
+
+interface JSONNestedNodeCircularPropsPassedThroughJSONNode
+  extends JSONNestedNodeCircularPropsPassedThroughJSONTree {
+  circularCache?: any[];
+  isCircular?: boolean;
+  level?: number;
+}
+export type CircularPropsPassedThroughJSONNode = SharedCircularPropsProvidedByJSONTree &
+  JSONValueNodeCircularPropsPassedThroughJSONTree &
+  JSONNestedNodeCircularPropsPassedThroughJSONNode;
+
+export interface JSONNestedNodeCircularPropsPassedThroughJSONNestedNode
+  extends JSONNestedNodeCircularPropsPassedThroughJSONNode {
+  circularCache: any[];
+  level: number;
+}
+export type CircularPropsPassedThroughJSONNestedNode = SharedCircularPropsProvidedByJSONTree &
+  JSONValueNodeCircularPropsPassedThroughJSONTree &
+  JSONNestedNodeCircularPropsPassedThroughJSONNestedNode;
+
+export type CircularPropsPassedThroughRenderChildNodes = SharedCircularPropsProvidedByJSONTree &
+  JSONValueNodeCircularPropsPassedThroughJSONTree &
+  JSONNestedNodeCircularPropsPassedThroughJSONNestedNode;
+
+export type CircularPropsPassedThroughItemRange = SharedCircularPropsProvidedByJSONTree &
+  JSONValueNodeCircularPropsPassedThroughJSONTree &
+  JSONNestedNodeCircularPropsPassedThroughJSONNestedNode;
diff --git a/packages/react-json-tree/src/utils/hexToRgb.ts b/packages/react-json-tree/src/utils/hexToRgb.ts
deleted file mode 100644
index 08a29b26..00000000
--- a/packages/react-json-tree/src/utils/hexToRgb.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-export default function(hex) {
-  const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
-  return result
-    ? {
-        r: parseInt(result[1], 16),
-        g: parseInt(result[2], 16),
-        b: parseInt(result[3], 16)
-      }
-    : null;
-}
diff --git a/packages/react-json-tree/tsconfig.json b/packages/react-json-tree/tsconfig.json
index 9f461de1..7d512280 100644
--- a/packages/react-json-tree/tsconfig.json
+++ b/packages/react-json-tree/tsconfig.json
@@ -2,6 +2,7 @@
   "compilerOptions": {
     "target": "esnext",
     "module": "commonjs",
+    "jsx": "react",
     "declaration": true,
     "outDir": "lib",
     "strict": true,
diff --git a/yarn.lock b/yarn.lock
index 568a0155..6c3bdb2d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2652,6 +2652,19 @@
   resolved "https://registry.yarnpkg.com/@types/parse-json/-/parse-json-4.0.0.tgz#2f8bb441434d163b35fb8ffdccd7138927ffb8c0"
   integrity sha512-//oorEZjL6sbPcKUaCdIGlIUeH26mgzimjBB77G6XRgnDl/L5wOnpyBGRe/Mmf5CVW3PwEBE1NjiMZ/ssFh4wA==
 
+"@types/prop-types@*":
+  version "15.7.3"
+  resolved "https://registry.yarnpkg.com/@types/prop-types/-/prop-types-15.7.3.tgz#2ab0d5da2e5815f94b0b9d4b95d1e5f243ab2ca7"
+  integrity sha512-KfRL3PuHmqQLOG+2tGpRO26Ctg+Cq1E01D2DMriKEATHgWLfeNDmq9e29Q9WIky0dQ3NPkd1mzYH8Lm936Z9qw==
+
+"@types/react@^15.0.0 || ^16.0.0":
+  version "16.9.34"
+  resolved "https://registry.yarnpkg.com/@types/react/-/react-16.9.34.tgz#f7d5e331c468f53affed17a8a4d488cd44ea9349"
+  integrity sha512-8AJlYMOfPe1KGLKyHpflCg5z46n0b5DbRfqDksxBLBTUpB75ypDBAO9eCUcjNwE6LCUslwTz00yyG/X9gaVtow==
+  dependencies:
+    "@types/prop-types" "*"
+    csstype "^2.2.0"
+
 "@types/source-list-map@*":
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/@types/source-list-map/-/source-list-map-0.1.2.tgz#0078836063ffaf17412349bba364087e0ac02ec9"
@@ -5625,7 +5638,7 @@ cssstyle@^1.0.0:
   dependencies:
     cssom "0.3.x"
 
-csstype@^2.5.7:
+csstype@^2.2.0, csstype@^2.5.7:
   version "2.6.10"
   resolved "https://registry.yarnpkg.com/csstype/-/csstype-2.6.10.tgz#e63af50e66d7c266edb6b32909cfd0aabe03928b"
   integrity sha512-D34BqZU4cIlMCY93rZHbrq9pjTAQJ3U8S8rfBqjwHxkGPThWFjzZDQpgMJY0QViLxth6ZKYiwFBo14RdN44U/w==
@@ -13857,7 +13870,7 @@ react-treebeard@^3.1.0:
     shallowequal "^1.1.0"
     velocity-react "^1.4.1"
 
-react@^16.0.0, react@^16.4.0, react@^16.4.2, react@^16.7.0:
+"react@^15.0.0 || ^16.0.0", react@^16.0.0, react@^16.4.0, react@^16.4.2, react@^16.7.0:
   version "16.13.1"
   resolved "https://registry.yarnpkg.com/react/-/react-16.13.1.tgz#2e818822f1a9743122c063d6410d85c1e3afe48e"
   integrity sha512-YMZQQq32xHLX0bz5Mnibv1/LHb3Sqzngu7xstSM+vrkE5Kzr9xE0yMByK5kMoTK30YVJE61WfbxIFFvfeDKT1w==