diff --git a/server/text_generation_server/models/flash_causal_lm.py b/server/text_generation_server/models/flash_causal_lm.py
index 5ff951b3..225133f5 100644
--- a/server/text_generation_server/models/flash_causal_lm.py
+++ b/server/text_generation_server/models/flash_causal_lm.py
@@ -79,6 +79,16 @@ class FlashCausalLMBatch(Batch):
         dtype: torch.dtype,
         device: torch.device,
     ) -> "FlashCausalLMBatch":
+        batch_inputs = []
+        max_truncation = 0
+        for r in pb.requests:
+            batch_inputs.append(r.inputs)
+            max_truncation = max(max_truncation, r.truncate)
+
+        batch_tokenized_inputs = tokenizer(
+            batch_inputs, truncation=True, max_length=max_truncation
+        )["input_ids"]
+
         position_ids = []
         cu_seqlens = [0]
         max_seqlen = 0
@@ -106,13 +116,11 @@ class FlashCausalLMBatch(Batch):
         max_length = 0
 
         # Parse batch
-        for i, r in enumerate(pb.requests):
+        for i, (r, tokenized_input) in enumerate(zip(pb.requests, batch_tokenized_inputs)):
             # request id -> idx in list mapping
             requests_idx_mapping[r.id] = i
 
-            tokenized_input = tokenizer(
-                r.inputs, truncation=True, max_length=r.truncate
-            )["input_ids"]
+            tokenized_input = tokenized_input[-r.truncate:]
 
             input_length = len(tokenized_input)
             max_seqlen = max(max_seqlen, input_length)