diff --git a/tests/end2end/fixtures/quteprocess.py b/tests/end2end/fixtures/quteprocess.py
index c62de1dc9..0b5f683cc 100644
--- a/tests/end2end/fixtures/quteprocess.py
+++ b/tests/end2end/fixtures/quteprocess.py
@@ -784,13 +784,8 @@ class QuteProc(testprocess.Process):
         be compared.
         """
         __tracebackhide__ = lambda e: e.errisinstance(pytest.fail.Exception)
-        # Translate ... to ellipsis in YAML.
-        loader = yaml.SafeLoader(expected)
-        loader.add_constructor('!ellipsis', lambda loader, node: ...)
-        loader.add_implicit_resolver('!ellipsis', re.compile(r'\.\.\.'), None)
-
         data = self.get_session()
-        expected = loader.get_data()
+        expected = yaml.load(expected, Loader=YamlLoader)
         outcome = testutils.partial_compare(data, expected)
         if not outcome:
             msg = "Session comparison failed: {}".format(outcome.error)
@@ -798,6 +793,18 @@ class QuteProc(testprocess.Process):
             pytest.fail(msg)
 
 
+class YamlLoader(yaml.SafeLoader):
+
+    """Custom YAML loader used in compare_session."""
+
+    pass
+
+
+# Translate ... to ellipsis in YAML.
+YamlLoader.add_constructor('!ellipsis', lambda loader, node: ...)
+YamlLoader.add_implicit_resolver('!ellipsis', re.compile(r'\.\.\.'), None)
+
+
 def _xpath_escape(text):
     """Escape a string to be used in an XPath expression.