diff --git a/src/components/views/elements/AppTile.tsx b/src/components/views/elements/AppTile.tsx
index f55751420e..34c773d3c9 100644
--- a/src/components/views/elements/AppTile.tsx
+++ b/src/components/views/elements/AppTile.tsx
@@ -57,7 +57,6 @@ import { WidgetMessagingStore } from "../../../stores/widgets/WidgetMessagingSto
 import { SdkContextClass } from "../../../contexts/SDKContext";
 import { ModuleRunner } from "../../../modules/ModuleRunner";
 import { parseUrl } from "../../../utils/UrlUtils";
-import ThemeWatcher, { ThemeWatcherEvents } from "../../../settings/watchers/ThemeWatcher";
 
 interface IProps {
     app: IWidget | IApp;
@@ -116,7 +115,6 @@ interface IState {
     menuDisplayed: boolean;
     requiresClient: boolean;
     hasContextMenuOptions: boolean;
-    widgetUrl?: string;
 }
 
 export default class AppTile extends React.Component<IProps, IState> {
@@ -142,7 +140,7 @@ export default class AppTile extends React.Component<IProps, IState> {
     private sgWidget: StopGapWidget | null;
     private dispatcherRef?: string;
     private unmounted = false;
-    private themeWatcher = new ThemeWatcher();
+
     public constructor(props: IProps, context: ContextType<typeof MatrixClientContext>) {
         super(props);
         this.context = context; // XXX: workaround for lack of `declare` support on `public context!:` definition
@@ -269,7 +267,6 @@ export default class AppTile extends React.Component<IProps, IState> {
                 !newProps.userWidget,
                 newProps.onDeleteClick,
             ),
-            widgetUrl: this.sgWidget?.embedUrl,
         };
     }
 
@@ -355,8 +352,6 @@ export default class AppTile extends React.Component<IProps, IState> {
     }
 
     private setupSgListeners(): void {
-        this.themeWatcher.on(ThemeWatcherEvents.ThemeChange, this.onThemeChanged);
-        this.themeWatcher.start();
         this.sgWidget?.on("ready", this.onWidgetReady);
         this.sgWidget?.on("error:preparing", this.updateRequiresClient);
         // emits when the capabilities have been set up or changed
@@ -364,9 +359,7 @@ export default class AppTile extends React.Component<IProps, IState> {
     }
 
     private stopSgListeners(): void {
-        this.themeWatcher.stop();
         if (!this.sgWidget) return;
-        this.themeWatcher.off(ThemeWatcherEvents.ThemeChange, this.onThemeChanged);
         this.sgWidget?.off("ready", this.onWidgetReady);
         this.sgWidget.off("error:preparing", this.updateRequiresClient);
         this.sgWidget.off("capabilitiesNotified", this.updateRequiresClient);
@@ -389,7 +382,6 @@ export default class AppTile extends React.Component<IProps, IState> {
     private startWidget(): void {
         this.sgWidget?.prepare().then(() => {
             if (this.unmounted) return;
-            if (!this.state.initialising) return;
             this.setState({ initialising: false });
         });
     }
@@ -464,17 +456,6 @@ export default class AppTile extends React.Component<IProps, IState> {
         });
     };
 
-    private onThemeChanged = (): void => {
-        // Regenerate widget url when the theme changes
-        // this updates the url from e.g. `theme=light` to `theme=dark`
-        // We only do this with EC widgets where the theme prop is in the hash. If the widget puts the
-        // theme template variable outside the url hash this would cause a (IFrame) page reload on every theme change.
-        if (WidgetType.CALL.matches(this.props.app.type)) this.setState({ widgetUrl: this.sgWidget?.embedUrl });
-
-        // TODO: This is a stop gap solution to responsively update the theme of the widget.
-        // A new action should be introduced and the widget driver should be called here, so it informs the widget. (or connect to this by itself)
-    };
-
     private onAction = (payload: ActionPayload): void => {
         switch (payload.action) {
             case "m.sticker":
@@ -567,9 +548,9 @@ export default class AppTile extends React.Component<IProps, IState> {
             this.resetWidget(this.props);
             this.startMessaging();
 
-            if (this.iframe && this.state.widgetUrl) {
+            if (this.iframe && this.sgWidget) {
                 // Reload iframe
-                this.iframe.src = this.state.widgetUrl;
+                this.iframe.src = this.sgWidget.embedUrl;
             }
         });
     }
@@ -638,7 +619,7 @@ export default class AppTile extends React.Component<IProps, IState> {
             "mx_AppTileBody--mini": this.props.miniMode,
             "mx_AppTileBody--loading": this.state.loading,
             // We don't want mx_AppTileBody (rounded corners) for call widgets
-            "mx_AppTileBody--call": WidgetType.CALL.matches(this.props.app.type),
+            "mx_AppTileBody--call": this.props.app.type === WidgetType.CALL.preferred,
         });
         const appTileBodyStyles: CSSProperties = {};
         if (this.props.pointerEvents) {
@@ -667,7 +648,7 @@ export default class AppTile extends React.Component<IProps, IState> {
                     <AppPermission
                         roomId={this.props.room.roomId}
                         creatorUserId={this.props.creatorUserId}
-                        url={this.state.widgetUrl}
+                        url={this.sgWidget.embedUrl}
                         isRoomEncrypted={isEncrypted}
                         onPermissionGranted={this.grantWidgetPermission}
                     />
@@ -695,7 +676,7 @@ export default class AppTile extends React.Component<IProps, IState> {
                                 title={widgetTitle}
                                 allow={iframeFeatures}
                                 ref={this.iframeRefChange}
-                                src={this.state.widgetUrl}
+                                src={this.sgWidget.embedUrl}
                                 allowFullScreen={true}
                                 sandbox={sandboxFlags}
                             />
@@ -718,12 +699,7 @@ export default class AppTile extends React.Component<IProps, IState> {
                     const zIndexAboveOtherPersistentElements = 101;
 
                     appTileBody = (
-                        <div
-                            className="mx_AppTile_persistedWrapper"
-                            // We store the widget url to make it possible to test the value of the widgetUrl. since the iframe itself wont be here. (PersistedElement are in a different dom tree)
-                            data-test-widget-url={this.state.widgetUrl}
-                            data-testid="widget-app-tile"
-                        >
+                        <div className="mx_AppTile_persistedWrapper">
                             <PersistedElement
                                 zIndex={this.props.miniMode ? zIndexAboveOtherPersistentElements : 9}
                                 persistKey={this.persistKey}
diff --git a/src/settings/watchers/ThemeWatcher.ts b/src/settings/watchers/ThemeWatcher.ts
index e4e65d3b3b..79a63f5470 100644
--- a/src/settings/watchers/ThemeWatcher.ts
+++ b/src/settings/watchers/ThemeWatcher.ts
@@ -16,7 +16,6 @@ limitations under the License.
 */
 
 import { logger } from "matrix-js-sdk/src/logger";
-import { TypedEventEmitter } from "matrix-js-sdk/src/matrix";
 
 import SettingsStore from "../SettingsStore";
 import dis from "../../dispatcher/dispatcher";
@@ -26,15 +25,7 @@ import { findHighContrastTheme, setTheme } from "../../theme";
 import { ActionPayload } from "../../dispatcher/payloads";
 import { SettingLevel } from "../SettingLevel";
 
-export enum ThemeWatcherEvents {
-    ThemeChange = "theme_change",
-}
-
-type EventHandlerMap = {
-    [ThemeWatcherEvents.ThemeChange]: (theme: string) => void;
-};
-
-export default class ThemeWatcher extends TypedEventEmitter<ThemeWatcherEvents, EventHandlerMap> {
+export default class ThemeWatcher {
     private themeWatchRef: string | null;
     private systemThemeWatchRef: string | null;
     private dispatcherRef: string | null;
@@ -46,7 +37,6 @@ export default class ThemeWatcher extends TypedEventEmitter<ThemeWatcherEvents,
     private currentTheme: string;
 
     public constructor() {
-        super();
         this.themeWatchRef = null;
         this.systemThemeWatchRef = null;
         this.dispatcherRef = null;
@@ -96,7 +86,6 @@ export default class ThemeWatcher extends TypedEventEmitter<ThemeWatcherEvents,
         this.currentTheme = forceTheme === undefined ? this.getEffectiveTheme() : forceTheme;
         if (oldTheme !== this.currentTheme) {
             setTheme(this.currentTheme);
-            this.emit(ThemeWatcherEvents.ThemeChange, this.currentTheme);
         }
     }
 
diff --git a/src/stores/widgets/StopGapWidget.ts b/src/stores/widgets/StopGapWidget.ts
index 64e9a980d1..bec4371af2 100644
--- a/src/stores/widgets/StopGapWidget.ts
+++ b/src/stores/widgets/StopGapWidget.ts
@@ -44,6 +44,7 @@ import { MatrixClientPeg } from "../../MatrixClientPeg";
 import { OwnProfileStore } from "../OwnProfileStore";
 import WidgetUtils from "../../utils/WidgetUtils";
 import { IntegrationManagers } from "../../integrations/IntegrationManagers";
+import SettingsStore from "../../settings/SettingsStore";
 import { WidgetType } from "../../widgets/WidgetType";
 import ActiveWidgetStore from "../ActiveWidgetStore";
 import { objectShallowClone } from "../../utils/objects";
@@ -161,7 +162,6 @@ export class StopGapWidget extends EventEmitter {
     private readonly virtual: boolean;
     private readUpToMap: { [roomId: string]: string } = {}; // room ID to event ID
     private stickyPromise?: () => Promise<void>; // This promise will be called and needs to resolve before the widget will actually become sticky.
-    private themeWatcher = new ThemeWatcher();
 
     public constructor(private appTileProps: IAppTileProps) {
         super();
@@ -212,19 +212,13 @@ export class StopGapWidget extends EventEmitter {
 
     private runUrlTemplate(opts = { asPopout: false }): string {
         const fromCustomisation = WidgetVariableCustomisations?.provideVariables?.() ?? {};
-        let theme = this.themeWatcher.getEffectiveTheme();
-        if (theme.startsWith("custom-")) {
-            // simplify custom theme to only light/dark
-            const customTheme = getCustomTheme(theme.slice(7));
-            theme = customTheme.is_dark ? "dark" : "light";
-        }
         const defaults: ITemplateParams = {
             widgetRoomId: this.roomId,
             currentUserId: this.client.getUserId()!,
             userDisplayName: OwnProfileStore.instance.displayName ?? undefined,
             userHttpAvatarUrl: OwnProfileStore.instance.getHttpAvatarUrl() ?? undefined,
             clientId: ELEMENT_CLIENT_ID,
-            clientTheme: theme,
+            clientTheme: SettingsStore.getValue("theme"),
             clientLanguage: getUserLanguage(),
             deviceId: this.client.getDeviceId() ?? undefined,
             baseUrl: this.client.baseUrl,
diff --git a/src/theme.ts b/src/theme.ts
index d462db466c..8e2e893334 100644
--- a/src/theme.ts
+++ b/src/theme.ts
@@ -121,7 +121,7 @@ function clearCustomTheme(): void {
     // remove all css variables, we assume these are there because of the custom theme
     const inlineStyleProps = Object.values(document.body.style);
     for (const prop of inlineStyleProps) {
-        if (typeof prop === "string" && prop.startsWith("--")) {
+        if (prop.startsWith("--")) {
             document.body.style.removeProperty(prop);
         }
     }
diff --git a/test/components/views/elements/AppTile-test.tsx b/test/components/views/elements/AppTile-test.tsx
index b5510c7f3f..f15f0ce560 100644
--- a/test/components/views/elements/AppTile-test.tsx
+++ b/test/components/views/elements/AppTile-test.tsx
@@ -19,7 +19,7 @@ import { jest } from "@jest/globals";
 import { Room, MatrixClient } from "matrix-js-sdk/src/matrix";
 import { ClientWidgetApi, IWidget, MatrixWidgetType } from "matrix-widget-api";
 import { Optional } from "matrix-events-sdk";
-import { act, render, RenderResult, waitFor } from "@testing-library/react";
+import { act, render, RenderResult } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { SpiedFunction } from "jest-mock";
 import {
@@ -50,8 +50,6 @@ import { ElementWidget } from "../../../../src/stores/widgets/StopGapWidget";
 import { WidgetMessagingStore } from "../../../../src/stores/widgets/WidgetMessagingStore";
 import { ModuleRunner } from "../../../../src/modules/ModuleRunner";
 import { RoomPermalinkCreator } from "../../../../src/utils/permalinks/Permalinks";
-import { SettingLevel } from "../../../../src/settings/SettingLevel";
-import { WidgetType } from "../../../../src/widgets/WidgetType";
 
 jest.mock("../../../../src/stores/OwnProfileStore", () => ({
     OwnProfileStore: {
@@ -70,7 +68,6 @@ describe("AppTile", () => {
     const resizeNotifier = new ResizeNotifier();
     let app1: IApp;
     let app2: IApp;
-    let appElementCall: IApp;
 
     const waitForRps = (roomId: string) =>
         new Promise<void>((resolve) => {
@@ -123,17 +120,6 @@ describe("AppTile", () => {
             creatorUserId: cli.getSafeUserId(),
             avatar_url: undefined,
         };
-        appElementCall = {
-            id: "1",
-            eventId: "2",
-            roomId: "r2",
-            type: WidgetType.CALL.preferred,
-            url: "https://example.com#theme=$org.matrix.msc2873.client_theme",
-            name: "Element Call",
-            creatorUserId: cli.getSafeUserId(),
-            avatar_url: undefined,
-        };
-
         jest.spyOn(WidgetStore.instance, "getApps").mockImplementation((roomId: string): Array<IApp> => {
             if (roomId === "r1") return [app1];
             if (roomId === "r2") return [app2];
@@ -453,6 +439,7 @@ describe("AppTile", () => {
                 expect(moveToContainerSpy).toHaveBeenCalledWith(r1, app1, Container.Top);
             });
         });
+
         describe("with an existing widgetApi with requiresClient = false", () => {
             beforeEach(() => {
                 const api = {
@@ -479,68 +466,6 @@ describe("AppTile", () => {
         });
     });
 
-    describe("with an element call widget", () => {
-        beforeEach(() => {
-            document.body.style.setProperty("--custom-color", "red");
-            document.body.style.setProperty("normal-color", "blue");
-        });
-        it("should update the widget url on theme change", async () => {
-            const renderResult = render(
-                <MatrixClientContext.Provider value={cli}>
-                    <a href="http://themeb" data-mx-theme="light">
-                        A
-                    </a>
-                    <a href="http://themeA" data-mx-theme="dark">
-                        B
-                    </a>
-                    <AppTile key={appElementCall.id} app={appElementCall} room={r1} />
-                </MatrixClientContext.Provider>,
-            );
-            await waitFor(() => {
-                expect(renderResult.getByTestId("widget-app-tile").dataset.testWidgetUrl).toEqual(
-                    "https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F#theme=light",
-                );
-            });
-            await SettingsStore.setValue("theme", null, SettingLevel.DEVICE, "dark");
-            await waitFor(() => {
-                expect(renderResult.getByTestId("widget-app-tile").dataset.testWidgetUrl).toEqual(
-                    "https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F#theme=dark",
-                );
-            });
-            await SettingsStore.setValue("theme", null, SettingLevel.DEVICE, "light");
-            await waitFor(() => {
-                expect(renderResult.getByTestId("widget-app-tile").dataset.testWidgetUrl).toEqual(
-                    "https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F#theme=light",
-                );
-            });
-        });
-        it("should not update the widget url for non Element Call widgets on theme change", async () => {
-            const appNonElementCall = { ...appElementCall, type: MatrixWidgetType.Custom };
-            const renderResult = render(
-                <MatrixClientContext.Provider value={cli}>
-                    <a href="http://themeb" data-mx-theme="light">
-                        A
-                    </a>
-                    <a href="http://themeA" data-mx-theme="dark">
-                        B
-                    </a>
-                    <AppTile key={appNonElementCall.id} app={appNonElementCall} room={r1} />
-                </MatrixClientContext.Provider>,
-            );
-            await waitFor(() => {
-                expect(renderResult.getByTestId("widget-app-tile").dataset.testWidgetUrl).toEqual(
-                    "https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F#theme=light",
-                );
-            });
-            await SettingsStore.setValue("theme", null, SettingLevel.DEVICE, "dark");
-            await waitFor(() => {
-                expect(renderResult.getByTestId("widget-app-tile").dataset.testWidgetUrl).toEqual(
-                    "https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F#theme=light",
-                );
-            });
-        });
-    });
-
     describe("for a persistent app", () => {
         let renderResult: RenderResult;
 
diff --git a/test/components/views/elements/__snapshots__/AppTile-test.tsx.snap b/test/components/views/elements/__snapshots__/AppTile-test.tsx.snap
index 932306ac5c..92b89013e1 100644
--- a/test/components/views/elements/__snapshots__/AppTile-test.tsx.snap
+++ b/test/components/views/elements/__snapshots__/AppTile-test.tsx.snap
@@ -85,8 +85,6 @@ exports[`AppTile for a persistent app should render 1`] = `
   >
     <div
       class="mx_AppTile_persistedWrapper"
-      data-test-widget-url="https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F"
-      data-testid="widget-app-tile"
     >
       <div />
     </div>
@@ -174,8 +172,6 @@ exports[`AppTile for a pinned widget should render 1`] = `
     </div>
     <div
       class="mx_AppTile_persistedWrapper"
-      data-test-widget-url="https://example.com/?widgetId=1&parentUrl=http%3A%2F%2Flocalhost%2F"
-      data-testid="widget-app-tile"
     >
       <div />
     </div>
diff --git a/test/stores/widgets/StopGapWidget-test.ts b/test/stores/widgets/StopGapWidget-test.ts
index e190aa91c0..9d1ade0f39 100644
--- a/test/stores/widgets/StopGapWidget-test.ts
+++ b/test/stores/widgets/StopGapWidget-test.ts
@@ -28,7 +28,6 @@ import { VoiceBroadcastInfoEventType, VoiceBroadcastRecording } from "../../../s
 import { SdkContextClass } from "../../../src/contexts/SDKContext";
 import ActiveWidgetStore from "../../../src/stores/ActiveWidgetStore";
 import SettingsStore from "../../../src/settings/SettingsStore";
-import * as Theme from "../../../src/theme";
 
 jest.mock("matrix-widget-api/lib/ClientWidgetApi");
 
@@ -64,46 +63,18 @@ describe("StopGapWidget", () => {
         widget.stopMessaging();
     });
 
-    describe("url template", () => {
-        it("should replace parameters in widget url template", () => {
-            const originalGetValue = SettingsStore.getValue;
-            const spy = jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
-                if (setting === "theme") return "my-theme-for-testing";
-                return originalGetValue(setting);
-            });
-            expect(widget.embedUrl).toBe(
-                "https://example.org/?user-id=%40userId%3Amatrix.org&device-id=ABCDEFGHI&base-url=https%3A%2F%2Fmatrix-client.matrix.org&theme=my-theme-for-testing&widgetId=test&parentUrl=http%3A%2F%2Flocalhost%2F",
-            );
-            spy.mockRestore();
-        });
-        it("should replace custom theme with light/dark", () => {
-            const originalGetValue = SettingsStore.getValue;
-            const spy = jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
-                if (setting === "theme") return "custom-my-theme";
-                return originalGetValue(setting);
-            });
-            jest.spyOn(Theme, "getCustomTheme").mockReturnValue({ is_dark: false } as unknown as Theme.CustomTheme);
-            expect(widget.embedUrl).toBe(
-                "https://example.org/?user-id=%40userId%3Amatrix.org&device-id=ABCDEFGHI&base-url=https%3A%2F%2Fmatrix-client.matrix.org&theme=light&widgetId=test&parentUrl=http%3A%2F%2Flocalhost%2F",
-            );
-            jest.spyOn(Theme, "getCustomTheme").mockReturnValue({ is_dark: true } as unknown as Theme.CustomTheme);
-            expect(widget.embedUrl).toBe(
-                "https://example.org/?user-id=%40userId%3Amatrix.org&device-id=ABCDEFGHI&base-url=https%3A%2F%2Fmatrix-client.matrix.org&theme=dark&widgetId=test&parentUrl=http%3A%2F%2Flocalhost%2F",
-            );
-            spy.mockRestore();
-        });
-        it("should replace parameters in widget popoutUrl template", () => {
-            const originalGetValue = SettingsStore.getValue;
-            const spy = jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
-                if (setting === "theme") return "my-theme-for-testing";
-                return originalGetValue(setting);
-            });
-            expect(widget.popoutUrl).toBe(
-                "https://example.org/?user-id=%40userId%3Amatrix.org&device-id=ABCDEFGHI&base-url=https%3A%2F%2Fmatrix-client.matrix.org&theme=my-theme-for-testing",
-            );
-            spy.mockRestore();
+    it("should replace parameters in widget url template", () => {
+        const originGetValue = SettingsStore.getValue;
+        const spy = jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
+            if (setting === "theme") return "my-theme-for-testing";
+            return originGetValue(setting);
         });
+        expect(widget.embedUrl).toBe(
+            "https://example.org/?user-id=%40userId%3Amatrix.org&device-id=ABCDEFGHI&base-url=https%3A%2F%2Fmatrix-client.matrix.org&theme=my-theme-for-testing&widgetId=test&parentUrl=http%3A%2F%2Flocalhost%2F",
+        );
+        spy.mockClear();
     });
+
     it("feeds incoming to-device messages to the widget", async () => {
         const event = mkEvent({
             event: true,