diff --git a/problem_builder/answer.py b/problem_builder/answer.py
index 691b7f43..52dafcc8 100644
--- a/problem_builder/answer.py
+++ b/problem_builder/answer.py
@@ -229,7 +229,7 @@ def submit(self, submission):
     @property
     def status(self):
         answer_length_ok = self.student_input
-        if self.min_characters > 0:
+        if self.min_characters and self.min_characters > 0:
             answer_length_ok = len(self.student_input.strip()) >= self.min_characters
 
         return 'correct' if answer_length_ok else 'incorrect'