diff --git a/src/crewai/agent.py b/src/crewai/agent.py
index 382cad521..657f6c796 100644
--- a/src/crewai/agent.py
+++ b/src/crewai/agent.py
@@ -126,7 +126,7 @@ class Agent(BaseModel):
     i18n: I18N = Field(default=I18N(), description="Internationalization settings.")
     llm: Any = Field(
         default_factory=lambda: ChatOpenAI(
-            model=os.environ.get("OPENAI_MODEL_NAME", "gpt-4")
+            model=os.environ.get("OPENAI_MODEL_NAME", "gpt-4o")
         ),
         description="Language model that will run the agent.",
     )