diff --git a/crates/ml/src/trainers/dqn/trainer/constructor.rs b/crates/ml/src/trainers/dqn/trainer/constructor.rs
index 065130248..2b035187f 100644
--- a/crates/ml/src/trainers/dqn/trainer/constructor.rs
+++ b/crates/ml/src/trainers/dqn/trainer/constructor.rs
@@ -95,7 +95,7 @@ impl DQNTrainer {
 
         // batch_size == 0 -> auto-compute from VRAM (no artificial cap)
         if hyperparams.batch_size == 0 {
-            hyperparams.batch_size = max_safe_batch;
+            hyperparams.batch_size = max_safe_batch.min(8192);
             info!("AutoBatchSizer: batch_size auto-computed to {}", hyperparams.batch_size);
         }
 
@@ -106,7 +106,7 @@ impl DQNTrainer {
                 "DQN batch_size capped from {} -> {} (VRAM ceiling)",
                 hyperparams.batch_size, max_safe_batch
             );
-            hyperparams.batch_size = max_safe_batch;
+            hyperparams.batch_size = max_safe_batch.min(8192);
         }
 
         // Use override device if provided (hyperopt shares one CUDA context),