diff --git a/holoviews/plotting/bokeh/annotation.py b/holoviews/plotting/bokeh/annotation.py
index 6c21d228a5..722afbf650 100644
--- a/holoviews/plotting/bokeh/annotation.py
+++ b/holoviews/plotting/bokeh/annotation.py
@@ -65,8 +65,8 @@ def _init_glyph(self, plot, mapping, properties):
         """
         Returns a Bokeh glyph object.
         """
-        properties.pop('source')
-        properties.pop('legend')
+        properties = {p: v for p, v in properties.items()
+                      if p not in ['source', 'legend']}
         box = Span(level='overlay', **dict(mapping, **properties))
         plot.renderers.append(box)
         return None, box