diff --git a/pie/models/decoder.py b/pie/models/decoder.py
index 55b6cb1..a08c359 100644
--- a/pie/models/decoder.py
+++ b/pie/models/decoder.py
@@ -315,8 +315,7 @@ def loss(self, logits, targets):
         return loss
 
     def predict_max(self, enc_outs, lengths,
-                    max_seq_len=20, bos=None, eos=None,
-                    context=None):
+                    bos=None, eos=None, context=None):
         """
         Decoding routine for inference with step-wise argmax procedure
 
@@ -331,6 +330,8 @@ def predict_max(self, enc_outs, lengths,
         mask = torch.ones(batch, dtype=torch.int64, device=device)
         inp = torch.zeros(batch, dtype=torch.int64, device=device) + bos
         hyps, scores = [], 0
+        # Take the longest known token as the maximum sequence length.
+        max_seq_len = len(max(self.label_encoder.known_tokens, key=len))
 
         for _ in range(max_seq_len):
             if mask.sum().item() == 0: