diff --git a/mmocr/models/textrecog/losses/ctc_loss.py b/mmocr/models/textrecog/losses/ctc_loss.py
index 12567d25..31bc9b79 100644
--- a/mmocr/models/textrecog/losses/ctc_loss.py
+++ b/mmocr/models/textrecog/losses/ctc_loss.py
@@ -72,7 +72,10 @@ class CTCLoss(BaseRecogLoss):
         outputs = torch.log_softmax(outputs, dim=2)
         bsz, seq_len = outputs.size(0), outputs.size(1)
         outputs_for_loss = outputs.permute(1, 0, 2).contiguous()  # T * N * C
-        targets = [data_sample.gt_text.indexes for data_sample in data_samples]
+        targets = [
+            data_sample.gt_text.indexes[:seq_len]
+            for data_sample in data_samples
+        ]
         target_lengths = torch.IntTensor([len(t) for t in targets])
         target_lengths = torch.clamp(target_lengths, min=1, max=seq_len).long()
         input_lengths = torch.full(