diff --git a/build_results.py b/build_results.py
index aae6c3cdf1bf99878a1006c406527d9f88e5eef1..e0b7bc948ef04c7e45a852b71cda00cac6e4d6a2 100755
--- a/build_results.py
+++ b/build_results.py
@@ -232,6 +232,8 @@ def build_records(genotypes, SVSet, true_ones_records, filtered_records, gt_qual
         results = {}
         true_one = None
 
+        chromosome = None
+
         for node in components:
             names.append(node.id)
             if node.id in true_ones_records:
@@ -256,6 +258,7 @@ def build_records(genotypes, SVSet, true_ones_records, filtered_records, gt_qual
                     "qualities": gt_quality[node.id] if node.id in gt_quality else None
                 }
                 tools.add(tool_name)
+                chromosome = node.chrom
 
         if true_one is not None:
             records[true_one]["tools"] = results
@@ -267,7 +270,8 @@ def build_records(genotypes, SVSet, true_ones_records, filtered_records, gt_qual
                 "length": "",
                 "tools": results,
                 "orphan": True,
-                "genotypes": None
+                "genotypes": None,
+                "chromosome": chromosome
             }
 
         names.sort()