diff --git a/src/UrlParams.test.ts b/src/UrlParams.test.ts
index 47428ac6..f78ffae4 100644
--- a/src/UrlParams.test.ts
+++ b/src/UrlParams.test.ts
@@ -100,4 +100,95 @@ describe("UrlParams", () => {
       expect(getUrlParams("?preload=true&widgetId=12345").preload).toBe(true);
     });
   });
+
+  describe("returnToLobby", () => {
+    it("is true in SPA mode", () => {
+      expect(getUrlParams("?returnToLobby=false").returnToLobby).toBe(true);
+    });
+
+    it("defaults to false in widget mode", () => {
+      expect(
+        getUrlParams("?widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo")
+          .returnToLobby,
+      ).toBe(false);
+    });
+
+    it("respected in widget mode", () => {
+      expect(
+        getUrlParams(
+          "?returnToLobby=true&widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo",
+        ).returnToLobby,
+      ).toBe(true);
+    });
+  });
+
+  describe("userId", () => {
+    it("is ignored in SPA mode", () => {
+      expect(getUrlParams("?userId=asd").userId).toBe(null);
+    });
+
+    it("is parsed in widget mode", () => {
+      expect(
+        getUrlParams(
+          "?userId=asd&widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo",
+        ).userId,
+      ).toBe("asd");
+    });
+  });
+
+  describe("deviceId", () => {
+    it("is ignored in SPA mode", () => {
+      expect(getUrlParams("?deviceId=asd").deviceId).toBe(null);
+    });
+
+    it("is parsed in widget mode", () => {
+      expect(
+        getUrlParams(
+          "?deviceId=asd&widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo",
+        ).deviceId,
+      ).toBe("asd");
+    });
+  });
+
+  describe("baseUrl", () => {
+    it("is ignored in SPA mode", () => {
+      expect(getUrlParams("?baseUrl=asd").baseUrl).toBe(null);
+    });
+
+    it("is parsed in widget mode", () => {
+      expect(
+        getUrlParams(
+          "?baseUrl=asd&widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo",
+        ).baseUrl,
+      ).toBe("asd");
+    });
+  });
+
+  describe("viaServers", () => {
+    it("is ignored in widget mode", () => {
+      expect(
+        getUrlParams(
+          "?viaServers=asd&widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo",
+        ).viaServers,
+      ).toBe(null);
+    });
+
+    it("is parsed in SPA mode", () => {
+      expect(getUrlParams("?viaServers=asd").viaServers).toBe("asd");
+    });
+  });
+
+  describe("homeserver", () => {
+    it("is ignored in widget mode", () => {
+      expect(
+        getUrlParams(
+          "?homeserver=asd&widgetId=12345&parentUrl=https%3A%2F%2Flocalhost%2Ffoo",
+        ).homeserver,
+      ).toBe(null);
+    });
+
+    it("is parsed in SPA mode", () => {
+      expect(getUrlParams("?homeserver=asd").homeserver).toBe("asd");
+    });
+  });
 });
diff --git a/src/UrlParams.ts b/src/UrlParams.ts
index c87b79cc..e471a9d9 100644
--- a/src/UrlParams.ts
+++ b/src/UrlParams.ts
@@ -232,10 +232,10 @@ export const getUrlParams = (
     showControls: parser.getFlagParam("showControls", true),
     hideScreensharing: parser.getFlagParam("hideScreensharing"),
     e2eEnabled: parser.getFlagParam("enableE2EE", true),
-    userId: parser.getParam("userId"),
+    userId: isWidget ? parser.getParam("userId") : null,
     displayName: parser.getParam("displayName"),
-    deviceId: parser.getParam("deviceId"),
-    baseUrl: parser.getParam("baseUrl"),
+    deviceId: isWidget ? parser.getParam("deviceId") : null,
+    baseUrl: isWidget ? parser.getParam("baseUrl") : null,
     lang: parser.getParam("lang"),
     fonts: parser.getAllParams("font"),
     fontScale: Number.isNaN(fontScale) ? null : fontScale,
@@ -243,10 +243,10 @@ export const getUrlParams = (
     allowIceFallback: parser.getFlagParam("allowIceFallback"),
     perParticipantE2EE: parser.getFlagParam("perParticipantE2EE"),
     skipLobby: parser.getFlagParam("skipLobby"),
-    returnToLobby: parser.getFlagParam("returnToLobby"),
+    returnToLobby: isWidget ? parser.getFlagParam("returnToLobby") : true,
     theme: parser.getParam("theme"),
-    viaServers: parser.getParam("viaServers"),
-    homeserver: parser.getParam("homeserver"),
+    viaServers: !isWidget ? parser.getParam("viaServers") : null,
+    homeserver: !isWidget ? parser.getParam("homeserver") : null,
   };
 };