diff --git a/aqt/editor.py b/aqt/editor.py
index c87352058..ee4916709 100644
--- a/aqt/editor.py
+++ b/aqt/editor.py
@@ -296,8 +296,13 @@ def _filterHTML(html):
             tag.replaceWithChildren()
     # turn file:/// links into relative ones
     for tag in doc("img"):
-        if tag['src'].lower().startswith("file://"):
-            tag['src'] = os.path.basename(tag['src'])
+        try:
+            if tag['src'].lower().startswith("file://"):
+                tag['src'] = os.path.basename(tag['src'])
+        except KeyError:
+            # for some bizarre reason, mnemosyne removes src elements
+            # from missing media
+            pass
     # strip superfluous elements
     for elem in "html", "head", "body", "meta":
         for tag in doc(elem):