diff --git a/src/crewai/agents/agent_builder/base_agent.py b/src/crewai/agents/agent_builder/base_agent.py
index 32c3f9010..091690613 100644
--- a/src/crewai/agents/agent_builder/base_agent.py
+++ b/src/crewai/agents/agent_builder/base_agent.py
@@ -25,7 +25,6 @@ from crewai.security.security_config import SecurityConfig
 from crewai.tools.base_tool import BaseTool, Tool
 from crewai.utilities import I18N, Logger, RPMController
 from crewai.utilities.config import process_config
-from crewai.utilities.converter import Converter
 from crewai.utilities.string_utils import interpolate_only
 
 T = TypeVar("T", bound="BaseAgent")
@@ -199,7 +198,7 @@ class BaseAgent(ABC, BaseModel):
                 )
         return processed_tools
 
-    @field_validator("allowed_agents")
+    @field_validator("allowed_agents", mode="before")
     @classmethod
     def validate_allowed_agents(cls, allowed_agents: Optional[List[Union[str, "BaseAgent"]]]) -> Optional[List[Union[str, "BaseAgent"]]]:
         """Validate the allowed_agents list."""