diff --git a/app/app.py b/app/app.py
index 96ac8c4..069e667 100755
--- a/app/app.py
+++ b/app/app.py
@@ -7,7 +7,7 @@
 
 app = FastAPI(
     title="Grammatical Error Correction",
-    version=api_settings.version,
+    version=api_settings.version if api_settings.version else "dev",
     description="A service that performs automatic grammatical error correction."
 )
 
@@ -15,8 +15,7 @@
     CORSMiddleware,
     allow_origins=["*"],
     allow_methods=["*"],
-    allow_headers=["*"],
-    allow_credentials=True,
+    allow_headers=["*"]
 )
 
 
@@ -42,7 +41,7 @@ async def shutdown():
 @app.get('/health/startup', include_in_schema=False)
 @app.get('/health/liveness', include_in_schema=False)
 async def health_check():
-    # Returns 200 the connection to RabbitMQ is up
+    # Returns 200 if connection to RabbitMQ is up
     if mq_connector.channel is None or mq_connector.channel.is_closed:
         raise HTTPException(500)
     return "OK"
diff --git a/app/config.py b/app/config.py
index efe9e75..ff70c8e 100755
--- a/app/config.py
+++ b/app/config.py
@@ -1,3 +1,4 @@
+from typing import Optional
 from pydantic import BaseSettings, validator
 
 
@@ -14,9 +15,9 @@ class Config:
 
 
 class APISettings(BaseSettings):
-    version: str
     max_input_length: int = 10000
     languages: str = "et"  # comma-separated list of 2-letter codes
+    version: Optional[str]
 
     @validator('languages')
     def list_languages(cls, v):
diff --git a/requirements.txt b/requirements.txt
index 06482f0..e85c427 100755
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-aio-pika==8.0.3
-fastapi==0.78.0
-uvicorn==0.18.2
-pydantic==1.9.1
\ No newline at end of file
+aio-pika==9.4.0
+fastapi==0.109.2
+uvicorn==0.27.1
+pydantic<2.0.0
\ No newline at end of file