diff --git a/build/hydra.nix b/build/hydra.nix
index fc84fe6e..22676b98 100644
--- a/build/hydra.nix
+++ b/build/hydra.nix
@@ -47,8 +47,8 @@ in
       max_unsupported_time = 86400
 
       allow_import_from_derivation = false
-      
-      max_output_size = 3221225472 # 3 << 30 = 3 GB
+
+      max_output_size = 3421225472 # 3 << 30 + 200000000 = 3 GiB + 0.2 GB
       max_db_connections = 350
 
       queue_runner_metrics_address = [::]:9198