diff --git a/statelint/fields/common.py b/statelint/fields/common.py
index 7b674f3..3d8c5d1 100644
--- a/statelint/fields/common.py
+++ b/statelint/fields/common.py
@@ -4,6 +4,9 @@
 
 
 class Comparison(str, Enum):
+    def __str__(self) -> str:
+        return self.value
+
     STRING_EQUALS = "StringEquals"
     STRING_LESS_THAN = "StringLessThan"
     STRING_GREATER_THAN = "StringGreaterThan"
@@ -46,6 +49,9 @@ class Comparison(str, Enum):
 
 
 class StateType(str, Enum):
+    def __str__(self) -> str:
+        return self.value
+
     PASS = "Pass"
     SUCCEED = "Succeed"
     FAIL = "Fail"
diff --git a/statelint/problem/problem_type.py b/statelint/problem/problem_type.py
index 1936bba..bf5783d 100644
--- a/statelint/problem/problem_type.py
+++ b/statelint/problem/problem_type.py
@@ -2,6 +2,9 @@
 
 
 class ProblemType(str, Enum):
+    def __str__(self) -> str:
+        return self.value
+
     # type check
     FLOAT = "a Float"
     STRING = "a String"