diff --git a/quickwit/quickwit-config/resources/tests/config/quickwit.json b/quickwit/quickwit-config/resources/tests/config/quickwit.json
index 95a38567387..828ea718d59 100644
--- a/quickwit/quickwit-config/resources/tests/config/quickwit.json
+++ b/quickwit/quickwit-config/resources/tests/config/quickwit.json
@@ -48,7 +48,7 @@
         "split_store_max_num_bytes": "1T",
         "split_store_max_num_splits": 10000,
         "max_concurrent_split_uploads": 8,
-o
+        "max_merge_write_throughput": "100mb"
     },
     "ingest_api": {
         "replication_factor": 2
diff --git a/quickwit/quickwit-config/resources/tests/config/quickwit.toml b/quickwit/quickwit-config/resources/tests/config/quickwit.toml
index f420ba699d6..49f582fc0e0 100644
--- a/quickwit/quickwit-config/resources/tests/config/quickwit.toml
+++ b/quickwit/quickwit-config/resources/tests/config/quickwit.toml
@@ -38,7 +38,7 @@ enable_otlp_endpoint = true
 split_store_max_num_bytes = "1T"
 split_store_max_num_splits = 10_000
 max_concurrent_split_uploads = 8
-max_merge_write_throughput = 100mb
+max_merge_write_throughput = "100mb"
 
 [ingest_api]
 replication_factor = 2
diff --git a/quickwit/quickwit-config/src/node_config/serialize.rs b/quickwit/quickwit-config/src/node_config/serialize.rs
index 3e9cf661a08..240ba88ef03 100644
--- a/quickwit/quickwit-config/src/node_config/serialize.rs
+++ b/quickwit/quickwit-config/src/node_config/serialize.rs
@@ -556,7 +556,7 @@ mod tests {
                 max_concurrent_split_uploads: 8,
                 cpu_capacity: IndexerConfig::default_cpu_capacity(),
                 enable_cooperative_indexing: false,
-                max_merge_write_throughput: None,
+                max_merge_write_throughput: Some(ByteSize::mb(100)),
             }
         );
         assert_eq!(
@@ -814,11 +814,9 @@ mod tests {
             "QW_DATA_DIR".to_string(),
             data_dir_path.to_string_lossy().to_string(),
         );
-        assert!(
-            load_node_config_with_env(ConfigFormat::Toml, file_content.as_bytes(), &env_vars,)
-                .await
-                .is_ok()
-        );
+        load_node_config_with_env(ConfigFormat::Toml, file_content.as_bytes(), &env_vars)
+            .await
+            .unwrap();
     }
 
     #[tokio::test]