diff --git a/.changeset/fix-mixed-r2-buckets.md b/.changeset/fix-mixed-r2-buckets.md
new file mode 100644
index 0000000000..a89f3467d6
--- /dev/null
+++ b/.changeset/fix-mixed-r2-buckets.md
@@ -0,0 +1,7 @@
+---
+"miniflare": patch
+---
+
+fix: allow mixed `r2Buckets` records containing both string and object entries
+
+Previously, passing an `r2Buckets` config that mixed plain string values and object entries (e.g. `{ MY_BUCKET: "bucket-name", OTHER_BUCKET: { ... } }`) would cause Miniflare to throw an error. Both forms are now accepted and normalised correctly.
diff --git a/packages/miniflare/src/plugins/r2/index.ts b/packages/miniflare/src/plugins/r2/index.ts
index bdb87adedd..9792145cb7 100644
--- a/packages/miniflare/src/plugins/r2/index.ts
+++ b/packages/miniflare/src/plugins/r2/index.ts
@@ -26,14 +26,16 @@ import {
 export const R2OptionsSchema = z.object({
 	r2Buckets: z
 		.union([
-			z.record(z.string()),
 			z.record(
-				z.object({
-					id: z.string(),
-					remoteProxyConnectionString: z
-						.custom<RemoteProxyConnectionString>()
-						.optional(),
-				})
+				z.union([
+					z.string(),
+					z.object({
+						id: z.string(),
+						remoteProxyConnectionString: z
+							.custom<RemoteProxyConnectionString>()
+							.optional(),
+					}),
+				])
 			),
 			z.string().array(),
 		])
diff --git a/packages/miniflare/test/index.spec.ts b/packages/miniflare/test/index.spec.ts
index b97f61fbaa..bd8597da05 100644
--- a/packages/miniflare/test/index.spec.ts
+++ b/packages/miniflare/test/index.spec.ts
@@ -137,6 +137,18 @@ test("Miniflare: validates options", async ({ expect }) => {
 	);
 });
 
+test("Miniflare: accepts mixed r2Buckets record", () => {
+	const mf = new Miniflare({
+		modules: true,
+		script: "",
+		r2Buckets: {
+			LOCAL_BUCKET: "local-bucket",
+			REMOTE_BUCKET: { id: "remote-bucket" },
+		},
+	});
+	useDispose(mf);
+});
+
 test("Miniflare: ready returns copy of entry URL", async ({ expect }) => {
 	const mf = new Miniflare({
 		port: 0,