diff --git a/net_alerter/net_alerter.py b/net_alerter/net_alerter.py
index 5ff1d3b..3c81c07 100644
--- a/net_alerter/net_alerter.py
+++ b/net_alerter/net_alerter.py
@@ -100,7 +100,7 @@ def send_matrix_alert(msg: str) -> None:
         print(f"[warn] No MATRIX_ACCESS_TOKEN set, skipping alert", file=sys.stderr)
         return
     code = _do_send(MATRIX_ACCESS_TOKEN, msg)
-    if code in (401, 403):
+    if code == 401:
         print("[info] Token expired, refreshing...", file=sys.stderr)
         new_token = refresh_token()
         if new_token:
@@ -108,6 +108,10 @@ def send_matrix_alert(msg: str) -> None:
             _do_send(MATRIX_ACCESS_TOKEN, msg)
         else:
             print("[error] Could not refresh token, alert dropped", file=sys.stderr)
+    elif code == 403:
+        print("[error] Room permission denied (403) — check bot membership in room", file=sys.stderr)
+    elif code not in (200, 0):
+        print(f"[error] Matrix send failed with HTTP {code}", file=sys.stderr)
 
 
 def get_local_subnets() -> list[str]: