diff --git a/src/chap/backends/textgen.py b/src/chap/backends/textgen.py
index 949c67f..f857680 100644
--- a/src/chap/backends/textgen.py
+++ b/src/chap/backends/textgen.py
@@ -61,8 +61,8 @@ AI: Hello! How can I assist you today?"""
         full_prompt = session + [User(query)]
         del full_prompt[1:-max_query_size]
         new_data = old_data = full_query = "\n".join(
-            f"{role_map.get(q.role,'')}{q.content}\n" for q in full_prompt
-        ) + f"\n{role_map.get('assistant')}"
+            f"{role_map.get(q.role,)}{q.content}\n" for q in full_prompt
+        ) + f"\n{role_map.get(Role.ASSISTANT)}"
         try:
             async with websockets.connect(
                 f"ws://{self.parameters.server_hostname}:7860/queue/join"
diff --git a/src/chap/session.py b/src/chap/session.py
index 5868296..e680718 100644
--- a/src/chap/session.py
+++ b/src/chap/session.py
@@ -4,6 +4,7 @@
 
 from __future__ import annotations
 
+import enum
 import json
 import pathlib
 from dataclasses import asdict, dataclass
@@ -12,8 +13,7 @@ from typing import Union, cast
 from typing_extensions import TypedDict
 
 
-# not an enum.Enum because these objects are not json-serializable, sigh
-class Role:
+class Role(str, enum.Enum):
     ASSISTANT = "assistant"
     SYSTEM = "system"
     USER = "user"
@@ -23,7 +23,7 @@ class Role:
 class Message:
     """Represents one Message within a chap Session"""
 
-    role: str
+    role: Role
     content: str