1 files changed, 1 insertions, 1 deletions
diff --git a/prolog/util.py b/prolog/util.py
index c0f1ef5..644080d 100644
--- a/prolog/util.py
+++ b/prolog/util.py
@@ -28,7 +28,7 @@ class Token(namedtuple('Token', ['type', 'val', 'pos'])):
         return super(Token, cls).__new__(cls, type, val, pos)
 
     def __str__(self):
-        return self.val
+        return str(self.val)
 
     # Only consider type and value when comparing tokens. There is probably a
     # cleaner way of doing this.