diff --git a/fsl/fsleyes/views/plotpanel.py b/fsl/fsleyes/views/plotpanel.py
index 04d849ea17b782cf2fbf8066b86a9d370a1cca35..4bf22abdd6a467cc2cb064aed674817a4a4489fc 100644
--- a/fsl/fsleyes/views/plotpanel.py
+++ b/fsl/fsleyes/views/plotpanel.py
@@ -977,7 +977,10 @@ class OverlayPlotPanel(PlotPanel):
         # registered, from the same target.
         for overlay in allOverlays + targetOverlays:
 
-            targets, propNames = self.__refreshProps[overlay]
+            targets, propNames = self.__refreshProps.get(overlay, (None, None))
+
+            if targets is None:
+                continue
 
             ds          = self.__dataSeries[overlay]
             addListener = overlay in targetOverlays