diff --git a/statelint/fields/common.py b/statelint/fields/common.py
index 7b674f3..f61e63e 100644
--- a/statelint/fields/common.py
+++ b/statelint/fields/common.py
@@ -1,9 +1,9 @@
 import json
-from enum import Enum
+from enum import StrEnum
 from typing import Any
 
 
-class Comparison(str, Enum):
+class Comparison(StrEnum):
     STRING_EQUALS = "StringEquals"
     STRING_LESS_THAN = "StringLessThan"
     STRING_GREATER_THAN = "StringGreaterThan"
@@ -45,7 +45,7 @@ class Comparison(str, Enum):
     STRING_MATCHES = "StringMatches"
 
 
-class StateType(str, Enum):
+class StateType(StrEnum):
     PASS = "Pass"
     SUCCEED = "Succeed"
     FAIL = "Fail"
diff --git a/statelint/problem/problem_type.py b/statelint/problem/problem_type.py
index 1936bba..eaee10b 100644
--- a/statelint/problem/problem_type.py
+++ b/statelint/problem/problem_type.py
@@ -1,7 +1,7 @@
-from enum import Enum
+from enum import StrEnum
 
 
-class ProblemType(str, Enum):
+class ProblemType(StrEnum):
     # type check
     FLOAT = "a Float"
     STRING = "a String"