diff --git a/fastapi_jwt_auth/config.py b/fastapi_jwt_auth/config.py
index c81b50c..24bcd9c 100644
--- a/fastapi_jwt_auth/config.py
+++ b/fastapi_jwt_auth/config.py
@@ -5,12 +5,13 @@
     validator,
     StrictBool,
     StrictInt,
-    StrictStr
+    StrictStr,
+    StrictBytes
 )
 
 class LoadConfig(BaseModel):
     authjwt_token_location: Optional[Sequence[StrictStr]] = {'headers'}
-    authjwt_secret_key: Optional[StrictStr] = None
+    authjwt_secret_key: Optional[Union[StrictStr,StrictBytes]] = None
     authjwt_public_key: Optional[StrictStr] = None
     authjwt_private_key: Optional[StrictStr] = None
     authjwt_algorithm: Optional[StrictStr] = "HS256"