diff --git a/packages/opal-client/opal_client/engine/options.py b/packages/opal-client/opal_client/engine/options.py
index 04364321b..f552cb6c1 100644
--- a/packages/opal-client/opal_client/engine/options.py
+++ b/packages/opal-client/opal_client/engine/options.py
@@ -63,7 +63,8 @@ class OpaServerOptions(BaseModel):
         None, description="path of TLS private key file"
     )
     tls_cert_refresh_period: Optional[str] = Field(
-        None, description="how often OPA should check the TLS certificate and private key file for changes"
+        None,
+        description="how often OPA should check the TLS certificate and private key file for changes",
     )
     log_level: LogLevel = Field(LogLevel.info, description="log level for opa logs")
     files: Optional[List[str]] = Field(