diff --git a/activitypub.py b/activitypub.py
index ccb8655..f832d51 100644
--- a/activitypub.py
+++ b/activitypub.py
@@ -36,7 +36,7 @@ SUPPORTED_TYPES = (
 
 
 @app.get(f'/<regex("{common.DOMAIN_RE}"):domain>')
-@flask_util.cached(cache, CACHE_TIME)
+@flask_util.cached(cache, CACHE_TIME, http_5xx=True)
 def actor(domain):
     """Fetches a domain's h-card and converts to AS2 actor."""
     _, _, actor, _ = common.actor(domain)
diff --git a/add_webmention.py b/add_webmention.py
index 9815fb7..a64953b 100644
--- a/add_webmention.py
+++ b/add_webmention.py
@@ -16,7 +16,7 @@ LINK_HEADER = '<%s>; rel="webmention"'
 
 
 @app.get(r'/wm/<path:url>')
-@flask_util.cached(cache, common.CACHE_TIME)
+@flask_util.cached(cache, common.CACHE_TIME, http_5xx=True)
 def add_wm(url=None):
     """Proxies HTTP requests and adds Link header to our webmention endpoint."""
     url = urllib.parse.unquote(url)
diff --git a/redirect.py b/redirect.py
index e207620..e9530b5 100644
--- a/redirect.py
+++ b/redirect.py
@@ -42,7 +42,7 @@ _negotiator = ContentNegotiator(acceptable=[
 
 
 @app.get(r'/r/<path:to>')
-@flask_util.cached(cache, CACHE_TIME, headers=['Accept'])
+@flask_util.cached(cache, CACHE_TIME, headers=['Accept'], http_5xx=True)
 def redir(to):
     """301 redirect to the embedded fully qualified URL.
 
diff --git a/webfinger.py b/webfinger.py
index 763bde1..0890eff 100644
--- a/webfinger.py
+++ b/webfinger.py
@@ -29,7 +29,7 @@ class Actor(flask_util.XrdOrJrd):
 
     TODO: unify with common.actor()
     """
-    @flask_util.cached(cache, common.CACHE_TIME, headers=['Accept'])
+    @flask_util.cached(cache, common.CACHE_TIME, headers=['Accept'], http_5xx=True)
     def dispatch_request(self, *args, **kwargs):
         return super().dispatch_request(*args, **kwargs)