diff --git a/package.json b/package.json
index 7c008d5ccc..620957dd04 100644
--- a/package.json
+++ b/package.json
@@ -118,9 +118,11 @@
     "@peculiar/webcrypto": "^1.0.22",
     "@types/classnames": "^2.2.10",
     "@types/flux": "^3.1.9",
+    "@types/lodash": "^4.14.152",
     "@types/modernizr": "^3.5.3",
     "@types/qrcode": "^1.3.4",
     "@types/react": "16.9",
+    "@types/react-dom": "^16.9.8",
     "@types/zxcvbn": "^4.4.0",
     "babel-eslint": "^10.0.3",
     "babel-jest": "^24.9.0",
diff --git a/src/components/views/elements/Field.js b/src/components/views/elements/Field.tsx
similarity index 67%
rename from src/components/views/elements/Field.js
rename to src/components/views/elements/Field.tsx
index 2ebb90da26..100a6ebf56 100644
--- a/src/components/views/elements/Field.js
+++ b/src/components/views/elements/Field.tsx
@@ -15,10 +15,9 @@ limitations under the License.
 */
 
 import React from 'react';
-import PropTypes from 'prop-types';
 import classNames from 'classnames';
 import * as sdk from '../../../index';
-import { debounce } from 'lodash';
+import { debounce, Cancelable } from 'lodash';
 
 // Invoke validation from user input (when typing, etc.) at most once every N ms.
 const VALIDATION_THROTTLE_MS = 200;
@@ -29,51 +28,88 @@ function getId() {
     return `${BASE_ID}_${count++}`;
 }
 
-export default class Field extends React.PureComponent {
-    static propTypes = {
-        // The field's ID, which binds the input and label together. Immutable.
-        id: PropTypes.string,
-        // The element to create. Defaults to "input".
-        // To define options for a select, use <Field><option ... /></Field>
-        element: PropTypes.oneOf(["input", "select", "textarea"]),
-        // The field's type (when used as an <input>). Defaults to "text".
-        type: PropTypes.string,
-        // id of a <datalist> element for suggestions
-        list: PropTypes.string,
-        // The field's label string.
-        label: PropTypes.string,
-        // The field's placeholder string. Defaults to the label.
-        placeholder: PropTypes.string,
-        // The field's value.
-        // This is a controlled component, so the value is required.
-        value: PropTypes.string.isRequired,
-        // Optional component to include inside the field before the input.
-        prefix: PropTypes.node,
-        // Optional component to include inside the field after the input.
-        postfix: PropTypes.node,
-        // The callback called whenever the contents of the field
-        // changes.  Returns an object with `valid` boolean field
-        // and a `feedback` react component field to provide feedback
-        // to the user.
-        onValidate: PropTypes.func,
-        // If specified, overrides the value returned by onValidate.
-        flagInvalid: PropTypes.bool,
-        // If specified, contents will appear as a tooltip on the element and
-        // validation feedback tooltips will be suppressed.
-        tooltipContent: PropTypes.node,
-        // If specified alongside tooltipContent, the class name to apply to the
-        // tooltip itself.
-        tooltipClassName: PropTypes.string,
-        // If specified, an additional class name to apply to the field container
-        className: PropTypes.string,
-        // All other props pass through to the <input>.
-    };
+interface IProps extends React.HTMLAttributes<HTMLElement> {
+    // The field's ID, which binds the input and label together. Immutable.
+    id?: string,
+    // The element to create. Defaults to "input".
+    // To define options for a select, use <Field><option ... /></Field>
+    element?: InputType,
+    // The field's type (when used as an <input>). Defaults to "text".
+    type?: string,
+    // id of a <datalist> element for suggestions
+    list?: string,
+    // The field's label string.
+    label?: string,
+    // The field's placeholder string. Defaults to the label.
+    placeholder?: string,
+    // The field's value.
+    // This is a controlled component, so the value is required.
+    value: string,
+    // Optional component to include inside the field before the input.
+    prefixComponent?: React.ReactNode,
+    // Optional component to include inside the field after the input.
+    postfixComponent?: React.ReactNode,
+    // The callback called whenever the contents of the field
+    // changes.  Returns an object with `valid` boolean field
+    // and a `feedback` react component field to provide feedback
+    // to the user.
+    onValidate?: (
+        args: {value: string, focused: boolean, allowEmpty: boolean}
+    ) => {valid: boolean, feedback: React.ReactNode},
+    // If specified, overrides the value returned by onValidate.
+    flagInvalid?: boolean,
+    // If specified, contents will appear as a tooltip on the element and
+    // validation feedback tooltips will be suppressed.
+    tooltipContent?: React.ReactNode,
+    // If specified alongside tooltipContent, the class name to apply to the
+    // tooltip itself.
+    tooltipClassName?: string,
+    // If specified, an additional class name to apply to the field container
+    className?: string,
+    // All other props pass through to the <input>.
+}
 
+enum InputType {
+    INPUT = "input",
+    SELECT = "select",
+    TEXTAREA = "textarea",
+}
+
+interface IState {
+    valid: boolean,
+    feedback: React.ReactNode,
+    feedbackVisible: boolean,
+    focused: boolean,
+}
+
+export default class Field extends React.PureComponent<IProps, IState> {
+    private id: string;
+    private input: HTMLInputElement;
+
+    /*
+     * This was changed from throttle to debounce: this is more traditional for
+     * form validation since it means that the validation doesn't happen at all
+     * until the user stops typing for a bit (debounce defaults to not running on
+     * the leading edge). If we're doing an HTTP hit on each validation, we have more
+     * incentive to prevent validating input that's very unlikely to be valid.
+     * We may find that we actually want different behaviour for registration
+     * fields, in which case we can add some options to control it.
+     */
+    validateOnChange = debounce(() => {
+        this.validate({
+            focused: true,
+        });
+    }, VALIDATION_THROTTLE_MS);
+
+    focus() {
+        this.input.focus();
+    }
     constructor(props) {
         super(props);
         this.state = {
             valid: undefined,
             feedback: undefined,
+            feedbackVisible: false,
             focused: false,
         };
 
@@ -114,11 +150,7 @@ export default class Field extends React.PureComponent {
         }
     };
 
-    focus() {
-        this.input.focus();
-    }
-
-    async validate({ focused, allowEmpty = true }) {
+    async validate({ focused, allowEmpty = true }: {focused: boolean, allowEmpty?: boolean}) {
         if (!this.props.onValidate) {
             return;
         }
@@ -149,48 +181,37 @@ export default class Field extends React.PureComponent {
         }
     }
 
-    /*
-     * This was changed from throttle to debounce: this is more traditional for
-     * form validation since it means that the validation doesn't happen at all
-     * until the user stops typing for a bit (debounce defaults to not running on
-     * the leading edge). If we're doing an HTTP hit on each validation, we have more
-     * incentive to prevent validating input that's very unlikely to be valid.
-     * We may find that we actually want different behaviour for registration
-     * fields, in which case we can add some options to control it.
-     */
-    validateOnChange = debounce(() => {
-        this.validate({
-            focused: true,
-        });
-    }, VALIDATION_THROTTLE_MS);
+
 
     render() {
         const {
-            element, prefix, postfix, className, onValidate, children,
+            element, prefixComponent, postfixComponent, className, onValidate, children,
             tooltipContent, flagInvalid, tooltipClassName, list, ...inputProps} = this.props;
 
         const inputElement = element || "input";
 
         // Set some defaults for the <input> element
         inputProps.type = inputProps.type || "text";
-        inputProps.ref = input => this.input = input;
+        const ref = input => this.input = input;
         inputProps.placeholder = inputProps.placeholder || inputProps.label;
         inputProps.id = this.id; // this overwrites the id from props
 
         inputProps.onFocus = this.onFocus;
         inputProps.onChange = this.onChange;
         inputProps.onBlur = this.onBlur;
-        inputProps.list = list;
 
-        const fieldInput = React.createElement(inputElement, inputProps, children);
+        // Appease typescript's inference
+        const inputProps_ = {...inputProps, ref, list};
+
+        const fieldInput = React.createElement(inputElement, inputProps_, children);
 
         let prefixContainer = null;
-        if (prefix) {
-            prefixContainer = <span className="mx_Field_prefix">{prefix}</span>;
+        if (prefixComponent) {
+            prefixContainer = <span className="mx_Field_prefix">{prefixComponent}</span>;
         }
         let postfixContainer = null;
-        if (postfix) {
-            postfixContainer = <span className="mx_Field_postfix">{postfix}</span>;
+        if (postfixComponent) {
+            postfixContainer = <span className="mx_Field_postfix">{postfixComponent}</span>;
         }
 
         const hasValidationFlag = flagInvalid !== null && flagInvalid !== undefined;
@@ -198,7 +219,7 @@ export default class Field extends React.PureComponent {
             // If we have a prefix element, leave the label always at the top left and
             // don't animate it, as it looks a bit clunky and would add complexity to do
             // properly.
-            mx_Field_labelAlwaysTopLeft: prefix,
+            mx_Field_labelAlwaysTopLeft: prefixComponent,
             mx_Field_valid: onValidate && this.state.valid === true,
             mx_Field_invalid: hasValidationFlag
                 ? flagInvalid
diff --git a/src/components/views/elements/Tooltip.js b/src/components/views/elements/Tooltip.tsx
similarity index 71%
rename from src/components/views/elements/Tooltip.js
rename to src/components/views/elements/Tooltip.tsx
index 4807ade3db..753052717c 100644
--- a/src/components/views/elements/Tooltip.js
+++ b/src/components/views/elements/Tooltip.tsx
@@ -18,67 +18,68 @@ limitations under the License.
 */
 
 
-import React from 'react';
+import React, { Component } from 'react';
 import ReactDOM from 'react-dom';
-import PropTypes from 'prop-types';
-import createReactClass from 'create-react-class';
 import dis from '../../../dispatcher/dispatcher';
 import classNames from 'classnames';
+import { ViewTooltipPayload } from '../../../dispatcher/payloads/ViewUserPayload';
+import { Action } from '../../../dispatcher/actions';
 
 const MIN_TOOLTIP_HEIGHT = 25;
 
-export default createReactClass({
-    displayName: 'Tooltip',
-
-    propTypes: {
+interface IProps {
         // Class applied to the element used to position the tooltip
-        className: PropTypes.string,
+        className: string,
         // Class applied to the tooltip itself
-        tooltipClassName: PropTypes.string,
+        tooltipClassName: string,
         // Whether the tooltip is visible or hidden.
         // The hidden state allows animating the tooltip away via CSS.
         // Defaults to visible if unset.
-        visible: PropTypes.bool,
+        visible: boolean,
         // the react element to put into the tooltip
-        label: PropTypes.node,
-    },
+        label: React.ReactNode,
+}
 
-    getDefaultProps() {
-        return {
-            visible: true,
-        };
-    },
+class Tooltip extends React.Component<IProps> {
+    private tooltipContainer: HTMLElement;
+    private tooltip: void | Element | Component<Element, any, any>;
+    private parent: Element;
+
+
+    static defaultProps = {
+        visible: true,
+    };
 
     // Create a wrapper for the tooltip outside the parent and attach it to the body element
-    componentDidMount: function() {
+    componentDidMount() {
         this.tooltipContainer = document.createElement("div");
         this.tooltipContainer.className = "mx_Tooltip_wrapper";
         document.body.appendChild(this.tooltipContainer);
-        window.addEventListener('scroll', this._renderTooltip, true);
+        window.addEventListener('scroll', this.renderTooltip, true);
 
-        this.parent = ReactDOM.findDOMNode(this).parentNode;
+        this.parent = ReactDOM.findDOMNode(this).parentNode as Element;
 
-        this._renderTooltip();
-    },
+        this.renderTooltip();
+    }
 
-    componentDidUpdate: function() {
-        this._renderTooltip();
-    },
+    componentDidUpdate() {
+        this.renderTooltip();
+    }
 
     // Remove the wrapper element, as the tooltip has finished using it
-    componentWillUnmount: function() {
-        dis.dispatch({
-            action: 'view_tooltip',
+    componentWillUnmount() {
+        dis.dispatch<ViewTooltipPayload>({
+            action: Action.ViewTooltip,
             tooltip: null,
             parent: null,
         });
 
         ReactDOM.unmountComponentAtNode(this.tooltipContainer);
         document.body.removeChild(this.tooltipContainer);
-        window.removeEventListener('scroll', this._renderTooltip, true);
-    },
+        window.removeEventListener('scroll', this.renderTooltip, true);
+    }
 
-    _updatePosition(style) {
+    private updatePosition(style: {[key: string]: any}) {
         const parentBox = this.parent.getBoundingClientRect();
         let offset = 0;
         if (parentBox.height > MIN_TOOLTIP_HEIGHT) {
@@ -91,16 +92,15 @@ export default createReactClass({
         style.top = (parentBox.top - 2) + window.pageYOffset + offset;
         style.left = 6 + parentBox.right + window.pageXOffset;
         return style;
-    },
+    }
 
-    _renderTooltip: function() {
+    private renderTooltip() {
         // Add the parent's position to the tooltips, so it's correctly
         // positioned, also taking into account any window zoom
         // NOTE: The additional 6 pixels for the left position, is to take account of the
         // tooltips chevron
-        const parent = ReactDOM.findDOMNode(this).parentNode;
-        let style = {};
-        style = this._updatePosition(style);
+        const parent = ReactDOM.findDOMNode(this).parentNode as Element;
+        const style = this.updatePosition({});
         // Hide the entire container when not visible. This prevents flashing of the tooltip
         // if it is not meant to be visible on first mount.
         style.display = this.props.visible ? "block" : "none";
@@ -118,21 +118,21 @@ export default createReactClass({
         );
 
         // Render the tooltip manually, as we wish it not to be rendered within the parent
-        this.tooltip = ReactDOM.render(tooltip, this.tooltipContainer);
+        this.tooltip = ReactDOM.render<Element>(tooltip, this.tooltipContainer);
 
         // Tell the roomlist about us so it can manipulate us if it wishes
-        dis.dispatch({
-            action: 'view_tooltip',
+        dis.dispatch<ViewTooltipPayload>({
+            action: Action.ViewTooltip,
             tooltip: this.tooltip,
             parent: parent,
         });
-    },
+    }
 
-    render: function() {
+    render() {
         // Render a placeholder
         return (
             <div className={this.props.className} >
             </div>
         );
-    },
-});
+    }
+}
diff --git a/src/components/views/settings/account/PhoneNumbers.js b/src/components/views/settings/account/PhoneNumbers.js
index ad2dabd8ae..02e995ac45 100644
--- a/src/components/views/settings/account/PhoneNumbers.js
+++ b/src/components/views/settings/account/PhoneNumbers.js
@@ -267,7 +267,7 @@ export default class PhoneNumbers extends React.Component {
                             label={_t("Phone Number")}
                             autoComplete="off"
                             disabled={this.state.verifying}
-                            prefix={phoneCountry}
+                            prefixComponent={phoneCountry}
                             value={this.state.newPhoneNumber}
                             onChange={this._onChangeNewPhoneNumber}
                         />
diff --git a/src/dispatcher/actions.ts b/src/dispatcher/actions.ts
index a2f9c3efe3..9cd9f7c9ba 100644
--- a/src/dispatcher/actions.ts
+++ b/src/dispatcher/actions.ts
@@ -38,5 +38,10 @@ export enum Action {
      * Open the user settings. No additional payload information required.
      */
     ViewUserSettings = "view_user_settings",
+
+    /**
+     * Sets the current tooltip
+     */
+    ViewTooltip = "view_tooltip",
 }
 
diff --git a/src/dispatcher/payloads/ViewUserPayload.ts b/src/dispatcher/payloads/ViewUserPayload.ts
index ed602d4e24..d1f6db8968 100644
--- a/src/dispatcher/payloads/ViewUserPayload.ts
+++ b/src/dispatcher/payloads/ViewUserPayload.ts
@@ -17,6 +17,7 @@ limitations under the License.
 import { RoomMember } from "matrix-js-sdk/src/models/room-member";
 import { ActionPayload } from "../payloads";
 import { Action } from "../actions";
+import { Component } from "react";
 
 export interface ViewUserPayload extends ActionPayload {
     action: Action.ViewUser,
@@ -27,3 +28,19 @@ export interface ViewUserPayload extends ActionPayload {
      */
     member?: RoomMember;
 }
+
+export interface ViewTooltipPayload extends ActionPayload {
+    action: Action.ViewTooltip,
+
+    /*
+     * The tooltip to render. If it's null the tooltip will not be rendered
+     * We need the void type because of typescript headaches.
+     */
+    tooltip: null | void | Element | Component<Element, any, any>;
+
+    /*
+     * The parent under which to render the tooltip. Can be null to remove
+     * the parent type.
+     */
+    parent: null | Element
+}
diff --git a/yarn.lock b/yarn.lock
index 93118dab22..9253442b7c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1265,6 +1265,11 @@
   resolved "https://registry.yarnpkg.com/@types/json-schema/-/json-schema-7.0.4.tgz#38fd73ddfd9b55abb1e1b2ed578cb55bd7b7d339"
   integrity sha512-8+KAKzEvSUdeo+kmqnKrqgeE+LcA0tjYWFY7RPProVYwnqDjukzO+3b6dLD56rYX5TdWejnEOLJYOIeh4CXKuA==
 
+"@types/lodash@^4.14.152":
+  version "4.14.152"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.152.tgz#7e7679250adce14e749304cdb570969f77ec997c"
+  integrity sha512-Vwf9YF2x1GE3WNeUMjT5bTHa2DqgUo87ocdgTScupY2JclZ5Nn7W2RLM/N0+oreexUk8uaVugR81NnTY/jNNXg==
+
 "@types/minimatch@*":
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
@@ -1292,6 +1297,13 @@
   dependencies:
     "@types/node" "*"
 
+"@types/react-dom@^16.9.8":
+  version "16.9.8"
+  resolved "https://registry.yarnpkg.com/@types/react-dom/-/react-dom-16.9.8.tgz#fe4c1e11dfc67155733dfa6aa65108b4971cb423"
+  integrity sha512-ykkPQ+5nFknnlU6lDd947WbQ6TE3NNzbQAkInC2EKY1qeYdTKp7onFusmYZb+ityzx2YviqT6BXSu+LyWWJwcA==
+  dependencies:
+    "@types/react" "*"
+
 "@types/react@*":
   version "16.9.35"
   resolved "https://registry.yarnpkg.com/@types/react/-/react-16.9.35.tgz#a0830d172e8aadd9bd41709ba2281a3124bbd368"