diff --git a/crow/include/crow/http_connection.h b/crow/include/crow/http_connection.h
index 87fa874..5cbe6ad 100644
--- a/crow/include/crow/http_connection.h
+++ b/crow/include/crow/http_connection.h
@@ -374,7 +374,7 @@
 
     if (res.body.empty() && !res.json_value.empty()) {
       res.json_mode();
-      res.body = res.json_value.dump();
+      res.body = res.json_value.dump(4);
     }
 
     if (!statusCodes.count(res.code)) {