diff --git a/changelog/3563.bugfix.rst b/changelog/3563.bugfix.rst
new file mode 100644
index 00000000000..8ba24c5dda3
--- /dev/null
+++ b/changelog/3563.bugfix.rst
@@ -0,0 +1 @@
+Warnings without ``location`` were reported as ``None``.  This is corrected to now report ``<undetermined location>``.
diff --git a/src/_pytest/terminal.py b/src/_pytest/terminal.py
index a985ab22191..9c4eec7531a 100644
--- a/src/_pytest/terminal.py
+++ b/src/_pytest/terminal.py
@@ -682,7 +682,7 @@ def summary_warnings(self):
 
             self.write_sep("=", "warnings summary", yellow=True, bold=False)
             for location, warning_records in grouped:
-                self._tw.line(str(location) or "<undetermined location>")
+                self._tw.line(str(location) if location else "<undetermined location>")
                 for w in warning_records:
                     lines = w.message.splitlines()
                     indented = "\n".join("  " + x for x in lines)
diff --git a/testing/test_terminal.py b/testing/test_terminal.py
index 68ce51d43cc..8f08ad34fa1 100644
--- a/testing/test_terminal.py
+++ b/testing/test_terminal.py
@@ -1025,7 +1025,10 @@ def pytest_terminal_summary(terminalreporter):
     """
     )
     result = testdir.runpytest("-rw")
-    result.stdout.fnmatch_lines(["*internal warning", "*== 1 warnings in *"])
+    result.stdout.fnmatch_lines(
+        ["<undetermined location>", "*internal warning", "*== 1 warnings in *"]
+    )
+    assert "None" not in result.stdout.str()
 
 
 @pytest.mark.parametrize(