diff --git a/packages/api/src/beacon/routes/beacon/block.ts b/packages/api/src/beacon/routes/beacon/block.ts
index 815815e9e365..ae92c53457cb 100644
--- a/packages/api/src/beacon/routes/beacon/block.ts
+++ b/packages/api/src/beacon/routes/beacon/block.ts
@@ -65,7 +65,7 @@ export type Api = {
   getBlock(
     blockId: BlockId,
     format?: BlockFormat
-  ): Promise<ApiClientResponse<{[HttpStatusCode.OK]: {data: allForks.SignedBeaconBlock}}>>;
+  ): Promise<ApiClientResponse<{[HttpStatusCode.OK]: Uint8Array | {data: allForks.SignedBeaconBlock}}>>;
 
   /**
    * Get block
@@ -79,11 +79,13 @@ export type Api = {
   ): Promise<
     ApiClientResponse<
       {
-        [HttpStatusCode.OK]: {
-          data: allForks.SignedBeaconBlock;
-          executionOptimistic: ExecutionOptimistic;
-          version: ForkName;
-        };
+        [HttpStatusCode.OK]:
+          | Uint8Array
+          | {
+              data: allForks.SignedBeaconBlock;
+              executionOptimistic: ExecutionOptimistic;
+              version: ForkName;
+            };
       },
       HttpStatusCode.BAD_REQUEST | HttpStatusCode.NOT_FOUND
     >
diff --git a/packages/api/src/beacon/server/beacon.ts b/packages/api/src/beacon/server/beacon.ts
index b5862f766b56..da5a0997a0d8 100644
--- a/packages/api/src/beacon/server/beacon.ts
+++ b/packages/api/src/beacon/server/beacon.ts
@@ -4,6 +4,41 @@ import {ServerRoutes, getGenericJsonServer} from "../../utils/server/index.js";
 import {ServerApi} from "../../interfaces.js";
 
 export function getRoutes(config: ChainForkConfig, api: ServerApi<Api>): ServerRoutes<Api, ReqTypes> {
-  // All routes return JSON, use a server auto-generator
-  return getGenericJsonServer<ServerApi<Api>, ReqTypes>({routesData, getReturnTypes, getReqSerializers}, config, api);
+  const reqSerializers = getReqSerializers(config);
+  const returnTypes = getReturnTypes();
+
+  // Most of routes return JSON, use a server auto-generator
+  const serverRoutes = getGenericJsonServer<ServerApi<Api>, ReqTypes>(
+    {routesData, getReturnTypes, getReqSerializers},
+    config,
+    api
+  );
+  return {
+    ...serverRoutes,
+    // Non-JSON routes. Return JSON or binary depending on "accept" header
+    getBlock: {
+      ...serverRoutes.getBlock,
+      handler: async (req) => {
+        const response = await api.getBlock(...reqSerializers.getBlock.parseReq(req));
+        if (response instanceof Uint8Array) {
+          // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
+          return Buffer.from(response);
+        } else {
+          return returnTypes.getBlock.toJson(response);
+        }
+      },
+    },
+    getBlockV2: {
+      ...serverRoutes.getBlockV2,
+      handler: async (req) => {
+        const response = await api.getBlockV2(...reqSerializers.getBlockV2.parseReq(req));
+        if (response instanceof Uint8Array) {
+          // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
+          return Buffer.from(response);
+        } else {
+          return returnTypes.getBlockV2.toJson(response);
+        }
+      },
+    },
+  };
 }