diff --git a/beeref/items.py b/beeref/items.py
index 3bbbd70..1dd9324 100644
--- a/beeref/items.py
+++ b/beeref/items.py
@@ -67,6 +67,7 @@ class BeePixmapItem(QtWidgets.QGraphicsPixmapItem):
         super().setScale(factor)
 
     def setZValue(self, value):
+        logger.debug(f'Setting z-value for image "{self.filename}" to {value}')
         super().setZValue(value)
         self.scene().max_z = max(self.scene().max_z, value)