diff --git a/src/@types/PushRules.ts b/src/@types/PushRules.ts
index 7864fe07c..fa404c43a 100644
--- a/src/@types/PushRules.ts
+++ b/src/@types/PushRules.ts
@@ -90,6 +90,8 @@ export interface ISenderNotificationPermissionCondition
     key: string;
 }
 
+// XXX: custom conditions are possible but always fail, and break the typescript discriminated union so ignore them here
+// IPushRuleCondition<Exclude<string, ConditionKind>> unfortunately does not resolve this at the time of writing.
 export type PushRuleCondition = IEventMatchCondition
     | IContainsDisplayNameCondition
     | IRoomMemberCountCondition
diff --git a/src/interactive-auth.ts b/src/interactive-auth.ts
index 7070bb7d5..28829e3f1 100644
--- a/src/interactive-auth.ts
+++ b/src/interactive-auth.ts
@@ -81,6 +81,15 @@ export interface IAuthDict {
     threepidCreds?: any;
 }
 
+class NoAuthFlowFoundError extends Error {
+    public name = "NoAuthFlowFoundError";
+
+    // eslint-disable-next-line @typescript-eslint/naming-convention, camelcase
+    constructor(m: string, public readonly required_stages: string[], public readonly flows: IFlow[]) {
+        super(m);
+    }
+}
+
 interface IOpts {
     matrixClient: MatrixClient;
     authData?: IAuthData;
@@ -574,16 +583,13 @@ export class InteractiveAuth {
                 return flow;
             }
         }
-        // Throw an error with a fairly generic description, but with more
-        // information such that the app can give a better one if so desired.
-        const err = new Error("No appropriate authentication flow found");
-        err.name = 'NoAuthFlowFoundError';
+
         const requiredStages: string[] = [];
         if (haveEmail) requiredStages.push(EMAIL_STAGE_TYPE);
         if (haveMsisdn) requiredStages.push(MSISDN_STAGE_TYPE);
-        (err as any).required_stages = requiredStages;
-        (err as any).available_flows = flows;
-        throw err;
+        // Throw an error with a fairly generic description, but with more
+        // information such that the app can give a better one if so desired.
+        throw new NoAuthFlowFoundError("No appropriate authentication flow found", requiredStages, flows);
     }
 
     /**
diff --git a/src/pushprocessor.ts b/src/pushprocessor.ts
index 8a8d86a33..7e551202c 100644
--- a/src/pushprocessor.ts
+++ b/src/pushprocessor.ts
@@ -24,12 +24,14 @@ import {
     IContainsDisplayNameCondition,
     IEventMatchCondition,
     IPushRule,
+    IPushRules,
     IRoomMemberCountCondition,
     ISenderNotificationPermissionCondition,
     PushRuleAction,
     PushRuleActionName,
     PushRuleCondition,
     PushRuleKind,
+    PushRuleSet,
     TweakName,
 } from "./@types/PushRules";
 
@@ -45,18 +47,6 @@ const RULEKINDS_IN_ORDER = [
     PushRuleKind.Underride,
 ];
 
-interface IRuleset {
-    [PushRuleKind.ContentSpecific]: IPushRule[];
-    [PushRuleKind.Override]: IPushRule[];
-    [PushRuleKind.RoomSpecific]: IPushRule[];
-    [PushRuleKind.SenderSpecific]: IPushRule[];
-    [PushRuleKind.Underride]: IPushRule[];
-}
-
-export interface IRulesets {
-    global: IRuleset;
-}
-
 // The default override rules to apply to the push rules that arrive from the server.
 // We do this for two reasons:
 //   1. Synapse is unlikely to send us the push rule in an incremental sync - see
@@ -114,6 +104,13 @@ export interface IActionsObject {
 }
 
 export class PushProcessor {
+    /**
+     * Construct a Push Processor.
+     * @constructor
+     * @param {Object} client The Matrix client object to use
+     */
+    constructor(private readonly client: MatrixClient) {}
+
     /**
      * Convert a list of actions into a object with the actions as keys and their values
      * eg. [ 'notify', { set_tweak: 'sound', value: 'default' } ]
@@ -145,13 +142,13 @@ export class PushProcessor {
      * @param {object} incomingRules The client's existing push rules
      * @returns {object} The rewritten rules
      */
-    public static rewriteDefaultRules(incomingRules: IRulesets): IRulesets {
-        let newRules: IRulesets = JSON.parse(JSON.stringify(incomingRules)); // deep clone
+    public static rewriteDefaultRules(incomingRules: IPushRules): IPushRules {
+        let newRules: IPushRules = JSON.parse(JSON.stringify(incomingRules)); // deep clone
 
         // These lines are mostly to make the tests happy. We shouldn't run into these
         // properties missing in practice.
-        if (!newRules) newRules = {} as IRulesets;
-        if (!newRules.global) newRules.global = {} as IRuleset;
+        if (!newRules) newRules = {} as IPushRules;
+        if (!newRules.global) newRules.global = {} as PushRuleSet;
         if (!newRules.global.override) newRules.global.override = [];
 
         // Merge the client-level defaults with the ones from the server
@@ -179,14 +176,7 @@ export class PushProcessor {
 
     private static cachedGlobToRegex: Record<string, RegExp> = {}; // $glob: RegExp
 
-    /**
-     * Construct a Push Processor.
-     * @constructor
-     * @param {Object} client The Matrix client object to use
-     */
-    constructor(private readonly client: MatrixClient) {}
-
-    private matchingRuleFromKindSet(ev: MatrixEvent, kindset: IRuleset): IAnnotatedPushRule {
+    private matchingRuleFromKindSet(ev: MatrixEvent, kindset: PushRuleSet): IAnnotatedPushRule {
         for (let ruleKindIndex = 0; ruleKindIndex < RULEKINDS_IN_ORDER.length; ++ruleKindIndex) {
             const kind = RULEKINDS_IN_ORDER[ruleKindIndex];
             const ruleset = kindset[kind];
diff --git a/src/sync.ts b/src/sync.ts
index 776e7847a..70cefef7b 100644
--- a/src/sync.ts
+++ b/src/sync.ts
@@ -30,7 +30,7 @@ import * as utils from "./utils";
 import { IDeferred } from "./utils";
 import { Filter } from "./filter";
 import { EventTimeline } from "./models/event-timeline";
-import { IRulesets, PushProcessor } from "./pushprocessor";
+import { PushProcessor } from "./pushprocessor";
 import { logger } from './logger';
 import { InvalidStoreError } from './errors';
 import { IStoredClientOpts, MatrixClient, PendingEventOrdering } from "./client";
@@ -53,6 +53,7 @@ import { MatrixEvent } from "./models/event";
 import { MatrixError } from "./http-api";
 import { ISavedSync } from "./store";
 import { EventType } from "./@types/event";
+import { IPushRules } from "./@types/PushRules";
 
 const DEBUG = true;
 
@@ -1067,7 +1068,7 @@ export class SyncApi {
                     // will be updated when we receive push rules via getPushRules
                     // (see sync) before syncing over the network.
                     if (accountDataEvent.getType() === EventType.PushRules) {
-                        const rules = accountDataEvent.getContent<IRulesets>();
+                        const rules = accountDataEvent.getContent<IPushRules>();
                         client.pushRules = PushProcessor.rewriteDefaultRules(rules);
                     }
                     const prevEvent = prevEventsMap[accountDataEvent.getId()];