diff --git a/agent/requirements.txt b/agent/requirements.txt
index 725c4c1b0..57da0d4ff 100644
--- a/agent/requirements.txt
+++ b/agent/requirements.txt
@@ -9,7 +9,7 @@ python-dotenv
 pytest
 pytest-asyncio
 passlib[bcrypt]
-bcrypt>=3.2,<4.0
+bcrypt>=3.2,<4.1  # passlib incompatible with bcrypt 4.1+
 python-jose[cryptography]
 
 # cache-bust-1772149708