diff --git a/cista/app.py b/cista/app.py
index 654e0be..d184b71 100644
--- a/cista/app.py
+++ b/cista/app.py
@@ -96,7 +96,7 @@ async def persist_auth_session(req, res):
     existing = getattr(req.ctx, "session", None)
     if isinstance(existing, dict) and existing.get("username") == username:
         return
-    session.create(res, username, secure=req.scheme == "https")
+    session.create(req, res, username)
 
 
 # Register either SSO proxy or built-in auth routes based on PASKIA_BACKEND_URL
diff --git a/cista/auth.py b/cista/auth.py
index f7fce87..81ce9f0 100644
--- a/cista/auth.py
+++ b/cista/auth.py
@@ -1107,7 +1107,7 @@ async def login_page(request):
 
     res = html(doc)
     if s is False:
-        session.delete(res)
+        session.delete(request, res)
     return res
 
 
@@ -1144,7 +1144,7 @@ async def login_post(request):
         session.flash(res, "Logged in")
     else:
         res = json({"data": {"username": username, "privileged": user.privileged}})
-    session.create(res, username, secure=request.scheme == "https")
+    session.create(request, res, username)
     return res
 
 
@@ -1157,7 +1157,7 @@ async def logout_post(request):
         res.cookies.add_cookie("flash", msg, max_age=5)
     else:
         res = json({"message": msg})
-    session.delete(res)
+    session.delete(request, res)
     return res
 
 
@@ -1189,7 +1189,7 @@ async def change_password(request):
         session.flash(res, "Password updated")
     else:
         res = json({"message": "Password updated"})
-    session.create(res, username, secure=request.scheme == "https")
+    session.create(request, res, username)
     return res
 
 
diff --git a/cista/session.py b/cista/session.py
index 8b0d33b..d0fa4b2 100644
--- a/cista/session.py
+++ b/cista/session.py
@@ -4,6 +4,8 @@ from time import time
 # In-memory session store: token -> {"username": str, "exp": int}
 _sessions: dict[str, dict] = {}
 
+SESSION_COOKIE_NAME = "cista"
+
 max_age = 365 * 86400  # Seconds since last login
 
 
@@ -19,7 +21,7 @@ def _purge_expired() -> None:
 
 
 def get(request):
-    token = request.cookies.get("s")
+    token = request.cookies.get(SESSION_COOKIE_NAME)
     if token is None:
         return None
     s = _sessions.get(token)
@@ -31,15 +33,24 @@ def get(request):
     return s
 
 
-def create(res, username, *, secure: bool = True, **kwargs):
+def create(request, res, username, **kwargs):
     _purge_expired()
     token = _token()
     _sessions[token] = {"exp": int(time()) + max_age, "username": username, **kwargs}
-    res.cookies.add_cookie("s", token, httponly=True, max_age=max_age, secure=secure)
+    secure = request.scheme == "https"
+    res.cookies.add_cookie(
+        SESSION_COOKIE_NAME,
+        token,
+        httponly=True,
+        max_age=max_age,
+        secure=secure,
+        host_prefix=secure,
+    )
 
 
-def delete(res):
-    res.cookies.delete_cookie("s")
+def delete(request, res):
+    secure = request.scheme == "https"
+    res.cookies.delete_cookie(SESSION_COOKIE_NAME, host_prefix=secure)
 
 
 def flash(res, message: str | None):
diff --git a/tests/test_files_auth.py b/tests/test_files_auth.py
index 9199e6f..b8b9e3f 100644
--- a/tests/test_files_auth.py
+++ b/tests/test_files_auth.py
@@ -98,7 +98,7 @@ def _session_cookie_header(username: str) -> dict[str, str]:
         "exp": int(time()) + session.max_age,
         "username": username,
     }
-    return {"Cookie": f"s={token}"}
+    return {"Cookie": f"cista={token}"}
 
 
 @pytest.fixture