diff --git a/scripts/visualize_irregular.py b/scripts/visualize_irregular.py
index 601acf3d9..4595610b5 100644
--- a/scripts/visualize_irregular.py
+++ b/scripts/visualize_irregular.py
@@ -81,7 +81,8 @@ def shape_path(path_x, path_y, shape, is_hole=False):
         for defect in (solution_bin["defects"]
                        if "defects" in solution_bin else []):
             shape_path(defects_x[bin_pos], defects_y[bin_pos], defect["shape"])
-            for hole in defect["holes"]:
+            for hole in (defect["holes"]
+                         if "holes" in defect else []):
                 shape_path(defects_x[bin_pos], defects_y[bin_pos], hole, True)
         for solution_item in solution_bin["items"]:
             for item_shape in solution_item["item_shapes"]:
diff --git a/scripts/visualize_irregular_instance.py b/scripts/visualize_irregular_instance.py
index 4e0dba3ef..b6c6f910f 100644
--- a/scripts/visualize_irregular_instance.py
+++ b/scripts/visualize_irregular_instance.py
@@ -84,7 +84,8 @@ def shape_path(path_x, path_y, shape, is_hole=False):
                     defects_x[bin_type_id],
                     defects_y[bin_type_id],
                     defect["elements"])
-            for hole in defect["holes"]:
+            for hole in (defect["holes"]
+                         if "holes" in defect else []):
                 shape_path(
                         defects_x[bin_type_id],
                         defects_y[bin_type_id],
diff --git a/src/irregular/instance_builder.cpp b/src/irregular/instance_builder.cpp
index 98df7ba34..310da9970 100644
--- a/src/irregular/instance_builder.cpp
+++ b/src/irregular/instance_builder.cpp
@@ -344,7 +344,46 @@ void InstanceBuilder::read(
         if (json_item.contains("copies_min"))
             copies_min = json_item["copies_min"];
 
-        add_bin_type(shape, cost, copies, copies_min);
+        BinTypeId bin_type_id = add_bin_type(shape, cost, copies, copies_min);
+
+        // Read defects.
+        if (json_item.contains("defects")) {
+            for (auto it_defect = json_item["defects"].begin();
+                    it_defect != json_item["defects"].end();
+                    ++it_defect) {
+                auto json_defect = *it_defect;
+
+                // Read type.
+                std::cout << "read type" << std::endl;
+                DefectTypeId defect_type = -1;
+                if (json_defect.contains("defect_type"))
+                    defect_type = json_defect["defect_type"];
+
+                // Read shape.
+                std::cout << "read shape" << std::endl;
+                Shape shape = read_shape(json_defect);
+
+                // Read holes.
+                std::cout << "read holes" << std::endl;
+                std::vector<Shape> holes;
+                if (json_defect.contains("holes")) {
+                    for (auto it_hole = json_defect["holes"].begin();
+                            it_hole != json_defect["holes"].end();
+                            ++it_hole) {
+                        auto json_hole = *it_hole;
+                        Shape hole = read_shape(json_hole);
+                        holes.push_back(hole);
+                    }
+                }
+
+                // Add defect.
+                add_defect(
+                        bin_type_id,
+                        defect_type,
+                        shape,
+                        holes);
+            }
+        }
     }
 
     // Read item types.