diff --git a/lmcsc/common.py b/lmcsc/common.py
index 32337c4..93debd3 100644
--- a/lmcsc/common.py
+++ b/lmcsc/common.py
@@ -5,6 +5,7 @@
 OOV_CHAR = "□"
 
 MIN = -1e32
+HALF_MIN = -1e4
 MAX = 1e32
 EPS = 1e-7
 
diff --git a/lmcsc/generation.py b/lmcsc/generation.py
index c677687..88ba22e 100644
--- a/lmcsc/generation.py
+++ b/lmcsc/generation.py
@@ -17,7 +17,7 @@
     GenerateBeamDecoderOnlyOutput,
 )
 
-from lmcsc.common import MIN
+from lmcsc.common import HALF_MIN, MIN
 from lmcsc.obversation_generator import BaseObversationGenerator
 
 def token_transformation_to_probs(self, observed_sequence: str) -> Tuple[List[int], List[float], dict]:
@@ -289,7 +289,10 @@ def distortion_guided_beam_search(
 
     # template for the distortion model
     template_weight = self.probs_template * self.distortion_model_smoothing
-    template_weight[self.token_length > 1] = MIN
+    if template_weight.dtype == torch.float16:
+        template_weight[self.token_length > 1] = HALF_MIN
+    else:
+        template_weight[self.token_length > 1] = MIN
 
     # clear the cache
     self.cache = {}
@@ -479,7 +482,10 @@ def distortion_guided_beam_search(
                 else:
                     this_text = ""
                 if this_text in predicted_sequences_set:
-                    next_token_scores[batch_i][candidate_i] = MIN
+                    if next_token_scores.dtype == torch.float16:
+                        next_token_scores[batch_i][candidate_i] = HALF_MIN
+                    else:
+                        next_token_scores[batch_i][candidate_i] = MIN
                 else:
                     predicted_sequences_set.add(this_text)
                 if len(predicted_sequences_set) > (max(2, 1 + n_eos_tokens) * num_beams):