@@ -292,7 +292,7 @@ def _repr_html_(self):
         else:
             params = ""
         return self.iframe.format(
-            src=html_escape(self.src),
+            src=html_escape(str(self.src)),
             width=html_escape(str(self.width)),
             height=html_escape(str(self.height)),
             params=params,
 
@@ -5,6 +5,7 @@
 import os
 import sys
 import warnings
+from pathlib import Path
 
 from unittest import mock
 
@@ -595,6 +596,12 @@ def test_iframe_escaping():
     assert 'width="400&quot; onload=&quot;alert(1)"' in html._repr_html_()
 
 
+def test_iframe_path_source():
+    """IFrame: pathlib sources are converted to strings before escaping."""
+    html = display.IFrame(Path("report&notes.html"), 400, 300)._repr_html_()
+    assert 'src="report&amp;notes.html"' in html
+
+
 def test_image_bad_filename_raises_proper_exception():
     with pytest.raises(FileNotFoundError):
         display.Image("/this/file/does/not/exist/")._repr_png_()