diff --git a/test/webview/ui/useVscodeTheme.test.ts b/test/webview/ui/useVscodeTheme.test.ts
index e83bbd4684..2e38837e16 100644
--- a/test/webview/ui/useVscodeTheme.test.ts
+++ b/test/webview/ui/useVscodeTheme.test.ts
@@ -1,4 +1,4 @@
-import { act, renderHook } from "@testing-library/react";
+import { act, cleanup, renderHook } from "@testing-library/react";
 import { afterEach, describe, expect, it } from "vitest";
 
 import { useVscodeTheme } from "@repo/ui";
@@ -12,6 +12,9 @@ function setThemeKind(kind: string | undefined): void {
 }
 
 afterEach(() => {
+	// Unmount before clearing the attribute so the MutationObserver
+	// callback doesn't trigger a state update on a mounted component.
+	cleanup();
 	setThemeKind(undefined);
 });
 
diff --git a/vitest.config.ts b/vitest.config.mts
similarity index 71%
rename from vitest.config.ts
rename to vitest.config.mts
index 521ce24ea9..3cc835357f 100644
--- a/vitest.config.ts
+++ b/vitest.config.mts
@@ -2,7 +2,7 @@ import path from "node:path";
 import { defineConfig } from "vitest/config";
 
 const webviewSharedAlias = path.resolve(
-	__dirname,
+	import.meta.dirname,
 	"packages/webview-shared/src",
 );
 
@@ -24,9 +24,12 @@ export default defineConfig({
 				},
 				resolve: {
 					alias: {
-						"@": path.resolve(__dirname, "src"),
+						"@": path.resolve(import.meta.dirname, "src"),
 						"@repo/webview-shared": webviewSharedAlias,
-						vscode: path.resolve(__dirname, "test/mocks/vscode.runtime.ts"),
+						vscode: path.resolve(
+							import.meta.dirname,
+							"test/mocks/vscode.runtime.ts",
+						),
 					},
 				},
 			},
@@ -43,11 +46,17 @@ export default defineConfig({
 				resolve: {
 					alias: {
 						"@repo/webview-shared": webviewSharedAlias,
-						"@repo/tasks": path.resolve(__dirname, "packages/tasks/src"),
-						"@repo/ui": path.resolve(__dirname, "packages/ui/src"),
-						"@repo/netcheck": path.resolve(__dirname, "packages/netcheck/src"),
+						"@repo/tasks": path.resolve(
+							import.meta.dirname,
+							"packages/tasks/src",
+						),
+						"@repo/ui": path.resolve(import.meta.dirname, "packages/ui/src"),
+						"@repo/netcheck": path.resolve(
+							import.meta.dirname,
+							"packages/netcheck/src",
+						),
 						"@repo/speedtest": path.resolve(
-							__dirname,
+							import.meta.dirname,
 							"packages/speedtest/src",
 						),
 					},