diff --git a/src/confdoc/validator/errors.py b/src/confdoc/validator/errors.py
index ae19ba5..5f9315c 100644
--- a/src/confdoc/validator/errors.py
+++ b/src/confdoc/validator/errors.py
@@ -132,7 +132,7 @@ class ErrorFormatter:
             actual_type = validator_error.get("found", "")
             return f"Expected type {expected_type}, but got {actual_type}."
         elif validator == "enum":
-            allowed = ", ".join(validator_value) if isinstance(validator_value, list) else str(validator_value)
+            allowed = ", ".join(str(e) for e in validator_value) if isinstance(validator_value, list) else str(validator_value)
             return f"Value must be one of: {allowed}"
         elif validator == "minimum":
             return f"Value must be greater than or equal to {validator_value}."