diff --git a/kraken/rpred.py b/kraken/rpred.py
index d41a11f67..179d9e872 100644
--- a/kraken/rpred.py
+++ b/kraken/rpred.py
@@ -285,8 +285,8 @@ def _recognize_baseline_line(self, line):
         pos = []
         conf = []
         for _, start, end, c in preds:
-            pos.append((self._scale_val(start, 0, self.box.size[0]),
-                        self._scale_val(end, 0, self.box.size[0])))
+            pos.append([self._scale_val(start, 0, self.box.size[0]),
+                        self._scale_val(end, 0, self.box.size[0])])
             conf.append(c)
         rec = BaselineOCRRecord(pred, pos, conf, line)
         if self.bidi_reordering:
@@ -307,7 +307,7 @@ def __len__(self):
 
     def _scale_val(self, val, min_val, max_val):
         return int(round(min(max(((val*self.net_scale)-self.pad)*self.in_scale, min_val), max_val-1)))
-    
+
     def _choose_legacy_polygon_extractor(self, net) -> bool:
         # grouping the checks here to display warnings only once
         if net.nn.use_legacy_polygons:
diff --git a/kraken/serialization.py b/kraken/serialization.py
index cb335a71b..b1e7ab9e8 100644
--- a/kraken/serialization.py
+++ b/kraken/serialization.py
@@ -165,7 +165,7 @@ def serialize(results: 'Segmentation',
         # addition to bounding boxes
         line = {'id': record.id,
                 'bbox': max_bbox([record.boundary]) if record.type == 'baselines' else record.bbox,
-                'cuts': record.cuts,
+                'cuts': [list(x) for x in record.cuts],
                 'confidences': record.confidences,
                 'recognition': [],
                 'boundary': [list(x) for x in record.boundary] if record.type == 'baselines' else [[record.bbox[0], record.bbox[1]],