diff --git a/src/components/views/dialogs/security/AccessSecretStorageDialog.js b/src/components/views/dialogs/security/AccessSecretStorageDialog.tsx
similarity index 79%
rename from src/components/views/dialogs/security/AccessSecretStorageDialog.js
rename to src/components/views/dialogs/security/AccessSecretStorageDialog.tsx
index f54a053984..3c09470b39 100644
--- a/src/components/views/dialogs/security/AccessSecretStorageDialog.js
+++ b/src/components/views/dialogs/security/AccessSecretStorageDialog.tsx
@@ -1,6 +1,5 @@
 /*
-Copyright 2018, 2019 New Vector Ltd
-Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
+Copyright 2018-2021 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -17,14 +16,15 @@ limitations under the License.
 
 import {debounce} from "lodash";
 import classNames from 'classnames';
-import React from 'react';
-import PropTypes from "prop-types";
+import React, {ChangeEvent, FormEvent} from 'react';
+import {ISecretStorageKeyInfo} from "matrix-js-sdk/src";
+
 import * as sdk from '../../../../index';
 import {MatrixClientPeg} from '../../../../MatrixClientPeg';
 import Field from '../../elements/Field';
 import AccessibleButton from '../../elements/AccessibleButton';
-
-import { _t } from '../../../../languageHandler';
+import {_t} from '../../../../languageHandler';
+import {IDialogProps} from "../IDialogProps";
 
 // Maximum acceptable size of a key file. It's 59 characters including the spaces we encode,
 // so this should be plenty and allow for people putting extra whitespace in the file because
@@ -34,22 +34,30 @@ const KEY_FILE_MAX_SIZE = 128;
 // Don't shout at the user that their key is invalid every time they type a key: wait a short time
 const VALIDATION_THROTTLE_MS = 200;
 
+interface IProps extends IDialogProps {
+    keyInfo: ISecretStorageKeyInfo;
+    checkPrivateKey: (k: {passphrase?: string, recoveryKey?: string}) => boolean;
+}
+
+interface IState {
+    recoveryKey: string;
+    recoveryKeyValid: boolean | null;
+    recoveryKeyCorrect: boolean | null;
+    recoveryKeyFileError: boolean | null;
+    forceRecoveryKey: boolean;
+    passPhrase: string;
+    keyMatches: boolean | null;
+}
+
 /*
  * Access Secure Secret Storage by requesting the user's passphrase.
  */
-export default class AccessSecretStorageDialog extends React.PureComponent {
-    static propTypes = {
-        // { passphrase, pubkey }
-        keyInfo: PropTypes.object.isRequired,
-        // Function from one of { passphrase, recoveryKey } -> boolean
-        checkPrivateKey: PropTypes.func.isRequired,
-    }
+export default class AccessSecretStorageDialog extends React.PureComponent<IProps, IState> {
+    private fileUpload = React.createRef<HTMLInputElement>();
 
     constructor(props) {
         super(props);
 
-        this._fileUpload = React.createRef();
-
         this.state = {
             recoveryKey: "",
             recoveryKeyValid: null,
@@ -61,21 +69,21 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
         };
     }
 
-    _onCancel = () => {
+    private onCancel = () => {
         this.props.onFinished(false);
-    }
+    };
 
-    _onUseRecoveryKeyClick = () => {
+    private onUseRecoveryKeyClick = () => {
         this.setState({
             forceRecoveryKey: true,
         });
-    }
+    };
 
-    _validateRecoveryKeyOnChange = debounce(() => {
-        this._validateRecoveryKey();
+    private validateRecoveryKeyOnChange = debounce(async () => {
+        await this.validateRecoveryKey();
     }, VALIDATION_THROTTLE_MS);
 
-    async _validateRecoveryKey() {
+    private async validateRecoveryKey() {
         if (this.state.recoveryKey === '') {
             this.setState({
                 recoveryKeyValid: null,
@@ -102,27 +110,27 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
         }
     }
 
-    _onRecoveryKeyChange = (e) => {
+    private onRecoveryKeyChange = (ev: ChangeEvent<HTMLInputElement>) => {
         this.setState({
-            recoveryKey: e.target.value,
+            recoveryKey: ev.target.value,
             recoveryKeyFileError: null,
         });
 
         // also clear the file upload control so that the user can upload the same file
         // the did before (otherwise the onchange wouldn't fire)
-        if (this._fileUpload.current) this._fileUpload.current.value = null;
+        if (this.fileUpload.current) this.fileUpload.current.value = null;
 
         // We don't use Field's validation here because a) we want it in a separate place rather
         // than in a tooltip and b) we want it to display feedback based on the uploaded file
         // as well as the text box. Ideally we would refactor Field's validation logic so we could
         // re-use some of it.
-        this._validateRecoveryKeyOnChange();
-    }
+        this.validateRecoveryKeyOnChange();
+    };
 
-    _onRecoveryKeyFileChange = async e => {
-        if (e.target.files.length === 0) return;
+    private onRecoveryKeyFileChange = async (ev: ChangeEvent<HTMLInputElement>) => {
+        if (ev.target.files.length === 0) return;
 
-        const f = e.target.files[0];
+        const f = ev.target.files[0];
 
         if (f.size > KEY_FILE_MAX_SIZE) {
             this.setState({
@@ -140,7 +148,7 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                     recoveryKeyFileError: null,
                     recoveryKey: contents.trim(),
                 });
-                this._validateRecoveryKey();
+                await this.validateRecoveryKey();
             } else {
                 this.setState({
                     recoveryKeyFileError: true,
@@ -150,14 +158,14 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                 });
             }
         }
+    };
+
+    private onRecoveryKeyFileUploadClick = () => {
+        this.fileUpload.current.click();
     }
 
-    _onRecoveryKeyFileUploadClick = () => {
-        this._fileUpload.current.click();
-    }
-
-    _onPassPhraseNext = async (e) => {
-        e.preventDefault();
+    private onPassPhraseNext = async (ev: FormEvent<HTMLFormElement>) => {
+        ev.preventDefault();
 
         if (this.state.passPhrase.length <= 0) return;
 
@@ -169,10 +177,10 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
         } else {
             this.setState({ keyMatches });
         }
-    }
+    };
 
-    _onRecoveryKeyNext = async (e) => {
-        e.preventDefault();
+    private onRecoveryKeyNext = async (ev: FormEvent<HTMLFormElement>) => {
+        ev.preventDefault();
 
         if (!this.state.recoveryKeyValid) return;
 
@@ -184,16 +192,16 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
         } else {
             this.setState({ keyMatches });
         }
-    }
+    };
 
-    _onPassPhraseChange = (e) => {
+    private onPassPhraseChange = (ev: ChangeEvent<HTMLInputElement>) => {
         this.setState({
-            passPhrase: e.target.value,
+            passPhrase: ev.target.value,
             keyMatches: null,
         });
-    }
+    };
 
-    getKeyValidationText() {
+    private getKeyValidationText(): string {
         if (this.state.recoveryKeyFileError) {
             return _t("Wrong file type");
         } else if (this.state.recoveryKeyCorrect) {
@@ -208,7 +216,8 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
     }
 
     render() {
-        const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
+        // Caution: Making this an import will break tests.
+        const BaseDialog = sdk.getComponent("views.dialogs.BaseDialog");
 
         const hasPassphrase = (
             this.props.keyInfo &&
@@ -244,18 +253,18 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                     {
                         button: s => <AccessibleButton className="mx_linkButton"
                             element="span"
-                            onClick={this._onUseRecoveryKeyClick}
+                            onClick={this.onUseRecoveryKeyClick}
                         >
                             {s}
                         </AccessibleButton>,
                     },
                 )}</p>
 
-                <form className="mx_AccessSecretStorageDialog_primaryContainer" onSubmit={this._onPassPhraseNext}>
+                <form className="mx_AccessSecretStorageDialog_primaryContainer" onSubmit={this.onPassPhraseNext}>
                     <input
                         type="password"
                         className="mx_AccessSecretStorageDialog_passPhraseInput"
-                        onChange={this._onPassPhraseChange}
+                        onChange={this.onPassPhraseChange}
                         value={this.state.passPhrase}
                         autoFocus={true}
                         autoComplete="new-password"
@@ -264,9 +273,9 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                     {keyStatus}
                     <DialogButtons
                         primaryButton={_t('Continue')}
-                        onPrimaryButtonClick={this._onPassPhraseNext}
+                        onPrimaryButtonClick={this.onPassPhraseNext}
                         hasCancel={true}
-                        onCancel={this._onCancel}
+                        onCancel={this.onCancel}
                         focus={false}
                         primaryDisabled={this.state.passPhrase.length === 0}
                     />
@@ -291,7 +300,7 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
 
                 <form
                     className="mx_AccessSecretStorageDialog_primaryContainer"
-                    onSubmit={this._onRecoveryKeyNext}
+                    onSubmit={this.onRecoveryKeyNext}
                     spellCheck={false}
                     autoComplete="off"
                 >
@@ -301,7 +310,7 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                                 type="password"
                                 label={_t('Security Key')}
                                 value={this.state.recoveryKey}
-                                onChange={this._onRecoveryKeyChange}
+                                onChange={this.onRecoveryKeyChange}
                                 forceValidity={this.state.recoveryKeyCorrect}
                                 autoComplete="off"
                             />
@@ -312,10 +321,10 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                         <div>
                             <input type="file"
                                 className="mx_AccessSecretStorageDialog_recoveryKeyEntry_fileInput"
-                                ref={this._fileUpload}
-                                onChange={this._onRecoveryKeyFileChange}
+                                ref={this.fileUpload}
+                                onChange={this.onRecoveryKeyFileChange}
                             />
-                            <AccessibleButton kind="primary" onClick={this._onRecoveryKeyFileUploadClick}>
+                            <AccessibleButton kind="primary" onClick={this.onRecoveryKeyFileUploadClick}>
                                 {_t("Upload")}
                             </AccessibleButton>
                         </div>
@@ -323,11 +332,11 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                     {recoveryKeyFeedback}
                     <DialogButtons
                         primaryButton={_t('Continue')}
-                        onPrimaryButtonClick={this._onRecoveryKeyNext}
+                        onPrimaryButtonClick={this.onRecoveryKeyNext}
                         hasCancel={true}
                         cancelButton={_t("Go Back")}
                         cancelButtonClass='danger'
-                        onCancel={this._onCancel}
+                        onCancel={this.onCancel}
                         focus={false}
                         primaryDisabled={!this.state.recoveryKeyValid}
                     />
@@ -341,9 +350,9 @@ export default class AccessSecretStorageDialog extends React.PureComponent {
                 title={title}
                 titleClass={titleClass}
             >
-            <div>
-                {content}
-            </div>
+                <div>
+                    {content}
+                </div>
             </BaseDialog>
         );
     }
diff --git a/test/components/views/dialogs/AccessSecretStorageDialog-test.js b/test/components/views/dialogs/AccessSecretStorageDialog-test.js
index 76412a6a82..13b39ab0d0 100644
--- a/test/components/views/dialogs/AccessSecretStorageDialog-test.js
+++ b/test/components/views/dialogs/AccessSecretStorageDialog-test.js
@@ -37,7 +37,7 @@ describe("AccessSecretStorageDialog", function() {
             recoveryKey: "a",
         });
         const e = { preventDefault: () => {} };
-        testInstance.getInstance()._onRecoveryKeyNext(e);
+        testInstance.getInstance().onRecoveryKeyNext(e);
     });
 
     it("Considers a valid key to be valid", async function() {
@@ -51,9 +51,9 @@ describe("AccessSecretStorageDialog", function() {
         stubClient();
         MatrixClientPeg.get().keyBackupKeyFromRecoveryKey = () => 'a raw key';
         MatrixClientPeg.get().checkSecretStorageKey = () => true;
-        testInstance.getInstance()._onRecoveryKeyChange(e);
+        testInstance.getInstance().onRecoveryKeyChange(e);
         // force a validation now because it debounces
-        await testInstance.getInstance()._validateRecoveryKey();
+        await testInstance.getInstance().validateRecoveryKey();
         const { recoveryKeyValid } = testInstance.getInstance().state;
         expect(recoveryKeyValid).toBe(true);
     });
@@ -69,9 +69,9 @@ describe("AccessSecretStorageDialog", function() {
         MatrixClientPeg.get().keyBackupKeyFromRecoveryKey = () => {
             throw new Error("that's no key");
         };
-        testInstance.getInstance()._onRecoveryKeyChange(e);
+        testInstance.getInstance().onRecoveryKeyChange(e);
         // force a validation now because it debounces
-        await testInstance.getInstance()._validateRecoveryKey();
+        await testInstance.getInstance().validateRecoveryKey();
 
         const { recoveryKeyValid, recoveryKeyCorrect } = testInstance.getInstance().state;
         expect(recoveryKeyValid).toBe(false);
@@ -98,8 +98,8 @@ describe("AccessSecretStorageDialog", function() {
         const e = { target: { value: "a" } };
         stubClient();
         MatrixClientPeg.get().isValidRecoveryKey = () => false;
-        testInstance.getInstance()._onPassPhraseChange(e);
-        await testInstance.getInstance()._onPassPhraseNext({ preventDefault: () => {} });
+        testInstance.getInstance().onPassPhraseChange(e);
+        await testInstance.getInstance().onPassPhraseNext({ preventDefault: () => {} });
         const notification = testInstance.root.findByProps({
             className: "mx_AccessSecretStorageDialog_keyStatus",
         });