diff --git a/jupyter_server/extension/manager.py b/jupyter_server/extension/manager.py
index e660b3dc14..e824d99729 100644
--- a/jupyter_server/extension/manager.py
+++ b/jupyter_server/extension/manager.py
@@ -322,7 +322,7 @@ def add_extension(self, extension_name, enabled=False):
             return True
         # Raise a warning if the extension cannot be loaded.
         except Exception as e:
-            if self.serverapp.reraise_server_extension_failures:
+            if self.serverapp and self.serverapp.reraise_server_extension_failures:
                 raise
             self.log.warning(
                 "%s | error adding extension (enabled: %s): %s",
@@ -343,7 +343,7 @@ def link_extension(self, name):
                 self.linked_extensions[name] = True
                 self.log.info("%s | extension was successfully linked.", name)
             except Exception as e:
-                if self.serverapp.reraise_server_extension_failures:
+                if self.serverapp and self.serverapp.reraise_server_extension_failures:
                     raise
                 self.log.warning("%s | error linking extension: %s", name, e, exc_info=True)
 
@@ -354,7 +354,7 @@ def load_extension(self, name):
             try:
                 extension.load_all_points(self.serverapp)
             except Exception as e:
-                if self.serverapp.reraise_server_extension_failures:
+                if self.serverapp and self.serverapp.reraise_server_extension_failures:
                     raise
                 self.log.warning("%s | extension failed loading with message: %s", name, e)
                 self.log.exception("%s | stack trace", name)
diff --git a/tests/extension/test_manager.py b/tests/extension/test_manager.py
index 2b52fea543..a6edddae15 100644
--- a/tests/extension/test_manager.py
+++ b/tests/extension/test_manager.py
@@ -1,5 +1,6 @@
 import os
 import unittest.mock as mock
+from contextlib import nullcontext
 
 import pytest
 from jupyter_core.paths import jupyter_config_path
@@ -96,39 +97,42 @@ def test_extension_manager_linked_extensions(jp_serverapp):
     assert name in manager.linked_extensions
 
 
-def test_extension_manager_fail_add(jp_serverapp):
+@pytest.mark.parametrize("has_app", [True, False])
+def test_extension_manager_fail_add(jp_serverapp, has_app):
     name = "tests.extension.notanextension"
-    manager = ExtensionManager(serverapp=jp_serverapp)
+    manager = ExtensionManager(serverapp=jp_serverapp if has_app else None)
     manager.add_extension(name, enabled=True)  # should only warn
     jp_serverapp.reraise_server_extension_failures = True
-    with pytest.raises(ExtensionModuleNotFound):
-        manager.add_extension(name, enabled=True)
+    with pytest.raises(ExtensionModuleNotFound) if has_app else nullcontext():
+        assert manager.add_extension(name, enabled=True) is False
 
 
-def test_extension_manager_fail_link(jp_serverapp):
+@pytest.mark.parametrize("has_app", [True, False])
+def test_extension_manager_fail_link(jp_serverapp, has_app):
     name = "tests.extension.mockextensions.app"
     with mock.patch(
         "tests.extension.mockextensions.app.MockExtensionApp.parse_command_line",
         side_effect=RuntimeError,
     ):
-        manager = ExtensionManager(serverapp=jp_serverapp)
+        manager = ExtensionManager(serverapp=jp_serverapp if has_app else None)
         manager.add_extension(name, enabled=True)
         manager.link_extension(name)  # should only warn
         jp_serverapp.reraise_server_extension_failures = True
-        with pytest.raises(RuntimeError):
+        with pytest.raises(RuntimeError) if has_app else nullcontext():
             manager.link_extension(name)
 
 
-def test_extension_manager_fail_load(jp_serverapp):
+@pytest.mark.parametrize("has_app", [True, False])
+def test_extension_manager_fail_load(jp_serverapp, has_app):
     name = "tests.extension.mockextensions.app"
     with mock.patch(
         "tests.extension.mockextensions.app.MockExtensionApp.initialize_handlers",
         side_effect=RuntimeError,
     ):
-        manager = ExtensionManager(serverapp=jp_serverapp)
+        manager = ExtensionManager(serverapp=jp_serverapp if has_app else None)
         manager.add_extension(name, enabled=True)
         manager.link_extension(name)
         manager.load_extension(name)  # should only warn
         jp_serverapp.reraise_server_extension_failures = True
-        with pytest.raises(RuntimeError):
+        with pytest.raises(RuntimeError) if has_app else nullcontext():
             manager.load_extension(name)