diff --git a/webapp/avatar.py b/webapp/avatar.py
index c6257f6..aa0aa8f 100644
--- a/webapp/avatar.py
+++ b/webapp/avatar.py
@@ -16,7 +16,7 @@ from PIL import Image, ImageDraw
 import flask
 import ldap
 
-from webapp import context, ldaputils
+from webapp import context, ldaputils, config
 
 bp = flask.Blueprint('avatar', __name__)
 log = logging.getLogger('ldap-web.avatar')
@@ -136,7 +136,7 @@ class AvatarCacheEntry:
 
     def __init__(self, uid: str, data: bytes):
         self.uid = uid
-        self.deadline = time.time() + 3600
+        self.deadline = time.time() + config.avatar_cache_timeout
         self.data = data
         self._converted = b""
 
diff --git a/webapp/config.py b/webapp/config.py
index a045518..4711642 100644
--- a/webapp/config.py
+++ b/webapp/config.py
@@ -28,6 +28,9 @@ ldap_active_groups = os.getenv('LDAPWEB_ACTIVE_GROUPS', 'fatty,starving,potato')
 ldap_admin_dn = os.getenv('LDAPWEB_ADMIN_DN', 'cn=ldapweb,ou=services,dc=hackerspace,dc=pl')
 ldap_admin_password = os.getenv('LDAPWEB_ADMIN_PASSWORD', 'unused')
 
+# avatar server
+avatar_cache_timeout = int(os.getenv('LDAPWEB_AVATAR_CACHE_TIMEOUT', '1800'))
+
 # LDAP attribute configuration
 
 readable_names = {