diff --git a/openbr/plugins/gui.cpp b/openbr/plugins/gui.cpp
index 80f6174..3aab218 100644
--- a/openbr/plugins/gui.cpp
+++ b/openbr/plugins/gui.cpp
@@ -764,7 +764,8 @@ public:
                         }
                         else
                         {
-                            dst[i].file.set(labelSet[idx], rectSet[idx]);
+                            if (labels.isEmpty()) dst[i].file.appendRect(rectSet[idx]);
+                            else dst[i].file.set(labelSet[idx], rectSet[idx]);
                         }
                     }
                 }