diff --git a/backend/app/main.py b/backend/app/main.py
index 742a2a0..33420d2 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -276,7 +276,7 @@ def extract_pdf_text_smart(pdf_content: bytes, max_chars: int = None) -> dict:
         }
 
 
-BACKEND_VERSION = "1.2.3"
+BACKEND_VERSION = "1.2.4"
 app = FastAPI(title="Checklist Inteligente API", version=BACKEND_VERSION)
 
 # S3/MinIO configuration
@@ -3172,7 +3172,9 @@ NOTA:
 
         if ai_config.provider == "openai":
             import openai
-            openai.api_key = ai_config.api_key
+            
+            # Crear cliente de OpenAI
+            client = openai.OpenAI(api_key=ai_config.api_key)
             
             # Construir mensaje según si es PDF o imagen
             if is_pdf:
@@ -3203,7 +3205,7 @@ NOTA:
                     }
                 ]
             
-            response = openai.ChatCompletion.create(
+            response = client.chat.completions.create(
                 model=ai_config.model_name,
                 messages=messages_content,
                 max_tokens=500
@@ -3347,8 +3349,11 @@ Responde en formato JSON:
   "confidence": 0.0-1.0
 }"""
 
-        response = openai.ChatCompletion.create(
-            model="gpt-4-vision-preview" if "gpt-4" in str(settings.OPENAI_API_KEY) else "gpt-4o",
+        # Crear cliente de OpenAI
+        client = openai.OpenAI(api_key=settings.OPENAI_API_KEY)
+        
+        response = client.chat.completions.create(
+            model="gpt-4o",
             messages=[
                 {
                     "role": "system",