diff --git a/website/src/scripts/analytics.ts b/website/src/scripts/analytics.ts
index 63fe9946..2dbb60f6 100644
--- a/website/src/scripts/analytics.ts
+++ b/website/src/scripts/analytics.ts
@@ -141,6 +141,7 @@ async function initializeConsent(allowAnalytics: boolean): Promise<void> {
 		});
 	};
 	const theme = () => document.documentElement.dataset.theme === 'light' ? 'light' : 'dark';
+	const initialTheme = theme();
 	wcp.init(document.documentElement.lang || 'en-US', banner, (error, consent) => {
 		if (error || !consent) {
 			console.error('Scope cookie consent could not initialize', error ?? new Error('Missing consent manager'));
@@ -150,10 +151,19 @@ async function initializeConsent(allowAnalytics: boolean): Promise<void> {
 		manageCookies.hidden = false;
 		manageCookies.addEventListener('click', () => consent.manageConsent());
 		onConsentChanged();
-		new MutationObserver(() => {
-			consent.applyTheme(theme());
-		}).observe(document.documentElement, { attributes: true, attributeFilter: ['data-theme'] });
-	}, onConsentChanged, theme());
+		let appliedTheme = initialTheme;
+		const applyTheme = () => {
+			const nextTheme = theme();
+			if (nextTheme === appliedTheme) return;
+			appliedTheme = nextTheme;
+			consent.applyTheme(nextTheme);
+		};
+		applyTheme();
+		new MutationObserver(applyTheme).observe(
+			document.documentElement,
+			{ attributes: true, attributeFilter: ['data-theme'] },
+		);
+	}, onConsentChanged, initialTheme);
 }
 
 const base = import.meta.env.BASE_URL.replace(/\/?$/, '/');
diff --git a/website/tests/analytics.spec.ts b/website/tests/analytics.spec.ts
index 24f17ef0..6df61ba7 100644
--- a/website/tests/analytics.spec.ts
+++ b/website/tests/analytics.spec.ts
@@ -161,10 +161,18 @@ test('stored consent initializes once and can be withdrawn and granted again', a
 test('consent UI follows Starlight theme changes', async ({ page }) => {
 	await mockPublishedSite(page);
 	await page.goto('https://microsoft.github.io/scope/');
-	await page.evaluate(() => { document.documentElement.dataset.theme = 'light'; });
-	await expect.poll(() => page.evaluate(() => window.scopeAnalyticsTest.appliedThemes)).toEqual(['light']);
-	await page.evaluate(() => { document.documentElement.dataset.theme = 'dark'; });
-	await expect.poll(() => page.evaluate(() => window.scopeAnalyticsTest.appliedThemes)).toEqual(['light', 'dark']);
+	await expect.poll(() => page.evaluate(() => Boolean(window.scopeAnalyticsTest.changeConsent))).toBe(true);
+	const initialTheme = await page.evaluate(
+		() => document.documentElement.dataset.theme === 'light' ? 'light' : 'dark',
+	);
+	const nextTheme = initialTheme === 'light' ? 'dark' : 'light';
+
+	await page.evaluate((theme) => { document.documentElement.dataset.theme = theme; }, initialTheme);
+	await expect.poll(() => page.evaluate(() => window.scopeAnalyticsTest.appliedThemes)).toEqual([]);
+	await page.evaluate((theme) => { document.documentElement.dataset.theme = theme; }, nextTheme);
+	await expect.poll(() => page.evaluate(() => window.scopeAnalyticsTest.appliedThemes)).toEqual([nextTheme]);
+	await page.evaluate((theme) => { document.documentElement.dataset.theme = theme; }, initialTheme);
+	await expect.poll(() => page.evaluate(() => window.scopeAnalyticsTest.appliedThemes)).toEqual([nextTheme, initialTheme]);
 });
 
 for (const options of [