diff --git a/libs/partners/mistralai/langchain_mistralai/chat_models.py b/libs/partners/mistralai/langchain_mistralai/chat_models.py
index 31739853f0d..804bb64f340 100644
--- a/libs/partners/mistralai/langchain_mistralai/chat_models.py
+++ b/libs/partners/mistralai/langchain_mistralai/chat_models.py
@@ -73,7 +73,7 @@ from langchain_core.pydantic_v1 import (
 )
 from langchain_core.runnables import Runnable, RunnableMap, RunnablePassthrough
 from langchain_core.tools import BaseTool
-from langchain_core.utils import convert_to_secret_str, get_from_dict_or_env
+from langchain_core.utils import secret_from_env
 from langchain_core.utils.function_calling import convert_to_openai_tool
 from langchain_core.utils.pydantic import is_basemodel_subclass
 
@@ -360,7 +360,10 @@ class ChatMistralAI(BaseChatModel):
 
     client: httpx.Client = Field(default=None)  #: :meta private:
     async_client: httpx.AsyncClient = Field(default=None)  #: :meta private:
-    mistral_api_key: Optional[SecretStr] = Field(default=None, alias="api_key")
+    mistral_api_key: Optional[SecretStr] = Field(
+        alias="api_key",
+        default_factory=secret_from_env("MISTRAL_API_KEY", default=None),
+    )
     endpoint: str = "https://api.mistral.ai/v1"
     max_retries: int = 5
     timeout: int = 120
@@ -465,15 +468,9 @@ class ChatMistralAI(BaseChatModel):
         combined = {"token_usage": overall_token_usage, "model_name": self.model}
         return combined
 
-    @root_validator()
+    @root_validator(pre=False, skip_on_failure=True)
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate api key, python package exists, temperature, and top_p."""
-
-        values["mistral_api_key"] = convert_to_secret_str(
-            get_from_dict_or_env(
-                values, "mistral_api_key", "MISTRAL_API_KEY", default=""
-            )
-        )
         api_key_str = values["mistral_api_key"].get_secret_value()
         # todo: handle retries
         if not values.get("client"):