diff --git a/changelog.d/16253.misc b/changelog.d/16253.misc
new file mode 100644
index 000000000000..9571a9175740
--- /dev/null
+++ b/changelog.d/16253.misc
@@ -0,0 +1 @@
+Fix `IntrospectionTokenCacheInvalidationTestCase` when `authlib` is not available.
diff --git a/tests/replication/test_intro_token_invalidation.py b/tests/replication/test_intro_token_invalidation.py
index f90678b6b1c8..8db463d3a1fc 100644
--- a/tests/replication/test_intro_token_invalidation.py
+++ b/tests/replication/test_intro_token_invalidation.py
@@ -17,8 +17,17 @@
 import synapse.rest.admin._base
 
 from tests.replication._base import BaseMultiWorkerStreamTestCase
+from tests.unittest import skip_unless
 
+try:
+    import authlib  # noqa: F401
 
+    HAS_AUTHLIB = True
+except ImportError:
+    HAS_AUTHLIB = False
+
+
+@skip_unless(HAS_AUTHLIB, "requires authlib")
 class IntrospectionTokenCacheInvalidationTestCase(BaseMultiWorkerStreamTestCase):
     servlets = [synapse.rest.admin.register_servlets]