diff --git a/src/backend/requirements.txt b/src/backend/requirements.txt
index dc9f84b..0e5c62a 100644
--- a/src/backend/requirements.txt
+++ b/src/backend/requirements.txt
@@ -6,6 +6,7 @@ pydantic-settings>=2.1.0
 email-validator>=2.0.0
 python-jose[cryptography]>=3.3.0
 passlib[bcrypt]>=1.7.4
+bcrypt>=4.0,<5.0  # Required for passlib compatibility
 crewai>=0.1.0
 anthropic>=0.18.0
 httpx>=0.26.0