diff --git a/.changeset/six-goats-ring.md b/.changeset/six-goats-ring.md
new file mode 100644
index 000000000000..b18993387de4
--- /dev/null
+++ b/.changeset/six-goats-ring.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-cloudflare': patch
+---
+
+fix: prevent vitest from hanging
diff --git a/packages/adapter-cloudflare-workers/index.js b/packages/adapter-cloudflare-workers/index.js
index 8a4f9252d1ac..9c842a7dddbe 100644
--- a/packages/adapter-cloudflare-workers/index.js
+++ b/packages/adapter-cloudflare-workers/index.js
@@ -149,29 +149,35 @@ export default function ({ config = 'wrangler.toml', platformProxy = {} } = {})
 			builder.writePrerendered(bucket_dir);
 		},
 
-		async emulate() {
-			const proxy = await getPlatformProxy(platformProxy);
-			const platform = /** @type {App.Platform} */ ({
-				env: proxy.env,
-				context: proxy.ctx,
-				caches: proxy.caches,
-				cf: proxy.cf
-			});
+		emulate() {
+			// we want to invoke `getPlatformProxy` only once, but await it only when it is accessed.
+			// If we would await it here, it would hang indefinitely because the platform proxy only resolves once a request happens
+			const getting_platform = (async () => {
+				const proxy = await getPlatformProxy(platformProxy);
+				const platform = /** @type {App.Platform} */ ({
+					env: proxy.env,
+					context: proxy.ctx,
+					caches: proxy.caches,
+					cf: proxy.cf
+				});
 
-			/** @type {Record<string, any>} */
-			const env = {};
-			const prerender_platform = /** @type {App.Platform} */ (/** @type {unknown} */ ({ env }));
+				/** @type {Record<string, any>} */
+				const env = {};
+				const prerender_platform = /** @type {App.Platform} */ (/** @type {unknown} */ ({ env }));
 
-			for (const key in proxy.env) {
-				Object.defineProperty(env, key, {
-					get: () => {
-						throw new Error(`Cannot access platform.env.${key} in a prerenderable route`);
-					}
-				});
-			}
+				for (const key in proxy.env) {
+					Object.defineProperty(env, key, {
+						get: () => {
+							throw new Error(`Cannot access platform.env.${key} in a prerenderable route`);
+						}
+					});
+				}
+				return { platform, prerender_platform };
+			})();
 
 			return {
-				platform: ({ prerender }) => {
+				platform: async ({ prerender }) => {
+					const { platform, prerender_platform } = await getting_platform;
 					return prerender ? prerender_platform : platform;
 				}
 			};
diff --git a/packages/adapter-cloudflare/index.js b/packages/adapter-cloudflare/index.js
index 0fe55898e569..cd2c62986cd8 100644
--- a/packages/adapter-cloudflare/index.js
+++ b/packages/adapter-cloudflare/index.js
@@ -144,29 +144,35 @@ export default function (options = {}) {
 				);
 			}
 		},
-		async emulate() {
-			const proxy = await getPlatformProxy(options.platformProxy);
-			const platform = /** @type {App.Platform} */ ({
-				env: proxy.env,
-				context: proxy.ctx,
-				caches: proxy.caches,
-				cf: proxy.cf
-			});
+		emulate() {
+			// we want to invoke `getPlatformProxy` only once, but await it only when it is accessed.
+			// If we would await it here, it would hang indefinitely because the platform proxy only resolves once a request happens
+			const getting_platform = (async () => {
+				const proxy = await getPlatformProxy(options.platformProxy);
+				const platform = /** @type {App.Platform} */ ({
+					env: proxy.env,
+					context: proxy.ctx,
+					caches: proxy.caches,
+					cf: proxy.cf
+				});
 
-			/** @type {Record<string, any>} */
-			const env = {};
-			const prerender_platform = /** @type {App.Platform} */ (/** @type {unknown} */ ({ env }));
+				/** @type {Record<string, any>} */
+				const env = {};
+				const prerender_platform = /** @type {App.Platform} */ (/** @type {unknown} */ ({ env }));
 
-			for (const key in proxy.env) {
-				Object.defineProperty(env, key, {
-					get: () => {
-						throw new Error(`Cannot access platform.env.${key} in a prerenderable route`);
-					}
-				});
-			}
+				for (const key in proxy.env) {
+					Object.defineProperty(env, key, {
+						get: () => {
+							throw new Error(`Cannot access platform.env.${key} in a prerenderable route`);
+						}
+					});
+				}
+				return { platform, prerender_platform };
+			})();
 
 			return {
-				platform: ({ prerender }) => {
+				platform: async ({ prerender }) => {
+					const { platform, prerender_platform } = await getting_platform;
 					return prerender ? prerender_platform : platform;
 				}
 			};