diff --git a/apps/desktop/src/lib/trpc/routers/auth/index.ts b/apps/desktop/src/lib/trpc/routers/auth/index.ts
index d60a4cddd0e..1e6bf29a696 100644
--- a/apps/desktop/src/lib/trpc/routers/auth/index.ts
+++ b/apps/desktop/src/lib/trpc/routers/auth/index.ts
@@ -5,7 +5,7 @@ import { observable } from "@trpc/server/observable";
 import { shell } from "electron";
 import { env } from "main/env.main";
 import { getDeviceName, getHashedDeviceId } from "main/lib/device-info";
-import { PROTOCOL_SCHEME } from "shared/constants";
+import { PLATFORM, PROTOCOL_SCHEME } from "shared/constants";
 import { env as sharedEnv } from "shared/env.shared";
 import { z } from "zod";
 import { publicProcedure, router } from "../..";
@@ -67,7 +67,8 @@ export const createAuthRouter = () => {
 
 		/**
 		 * Start OAuth sign-in flow.
-		 * Opens browser for OAuth, token delivered via deep link callback.
+		 * Opens browser for OAuth, token delivered via deep link on macOS
+		 * or localhost callback on Linux (where deep links are unreliable).
 		 */
 		signIn: publicProcedure
 			.input(z.object({ provider: z.enum(AUTH_PROVIDERS) }))
@@ -88,10 +89,13 @@ export const createAuthRouter = () => {
 					connectUrl.searchParams.set("provider", input.provider);
 					connectUrl.searchParams.set("state", state);
 					connectUrl.searchParams.set("protocol", PROTOCOL_SCHEME);
-					connectUrl.searchParams.set(
-						"local_callback",
-						`http://127.0.0.1:${sharedEnv.DESKTOP_NOTIFICATIONS_PORT}/auth/callback`,
-					);
+					// Only send local_callback on Linux where deep links are unreliable
+					if (PLATFORM.IS_LINUX) {
+						connectUrl.searchParams.set(
+							"local_callback",
+							`http://127.0.0.1:${sharedEnv.DESKTOP_NOTIFICATIONS_PORT}/auth/callback`,
+						);
+					}
 					await shell.openExternal(connectUrl.toString());
 					return { success: true };
 				} catch (err) {