diff --git a/python/sglang/srt/models/deepseek_v4.py b/python/sglang/srt/models/deepseek_v4.py
index 425261ff9..d31370da9 100644
--- a/python/sglang/srt/models/deepseek_v4.py
+++ b/python/sglang/srt/models/deepseek_v4.py
@@ -1045,6 +1045,10 @@ class DeepseekV4Model(nn.Module):
                 hidden_states = cp_split_and_rebuild_data(forward_batch, hidden_states)
             positions = cp_split_and_rebuild_position(forward_batch, positions)
 
+        # Upgrade lazy raw metadata on the main stream once before any layer
+        # forks alt-streams; later per-layer calls become no-ops.
+        forward_batch.attn_backend._maybe_upgrade_forward_metadata()
+
         for i in range(self.start_layer, self.end_layer):
             layer = self.layers[i]
             hidden_states = layer(