diff --git a/crates/ml/src/trainers/dqn/trainer/metrics.rs b/crates/ml/src/trainers/dqn/trainer/metrics.rs
index 9b1c4a4f6..b13f32e39 100644
--- a/crates/ml/src/trainers/dqn/trainer/metrics.rs
+++ b/crates/ml/src/trainers/dqn/trainer/metrics.rs
@@ -111,12 +111,12 @@ impl DQNTrainer {
                 let top5_coverage_pct = (top5_count as f64 / total_factored as f64) * 100.0;
                 metrics.add_metric("top5_coverage_pct", top5_coverage_pct);
             } else {
-                // Fallback: 5 exposure levels
+                // Fallback: exposure-only (9 levels)
                 let unique_actions = total_action_counts.iter()
                     .filter(|&&count| count > 0).count();
-                let action_diversity = (unique_actions as f64 / 5.0) * 100.0;
+                let action_diversity = (unique_actions as f64 / 9.0) * 100.0;
                 metrics.add_metric("action_diversity", action_diversity);
-                metrics.add_metric("action_space_size", 5.0);
+                metrics.add_metric("action_space_size", 9.0);
 
                 let active_threshold = (total_exposure as f64 * 0.005).max(1.0);
                 let active_count = total_action_counts.iter()
diff --git a/crates/ml/tests/smoke_test_real_data.rs b/crates/ml/tests/smoke_test_real_data.rs
index 93a800d74..02561eb43 100644
--- a/crates/ml/tests/smoke_test_real_data.rs
+++ b/crates/ml/tests/smoke_test_real_data.rs
@@ -883,9 +883,11 @@ async fn smoke_e2e_dqn_training_loop() {
         .copied()
         .unwrap_or(0.0);
     info!(action_space, action_diversity, total_actions, "Action metrics");
+    // Branching DQN: action_space=81 (9×3×3) when factored counts populated,
+    // or 9 (exposure-only fallback) for very short runs.
     assert!(
-        action_space > 5.0 || total_actions == 0.0,
-        "Branching DQN should report 81-action space, got {action_space}"
+        action_space >= 9.0 || total_actions == 0.0,
+        "Branching DQN should report >=9 action space, got {action_space}"
     );
 
     // 6. Gradient norms should be non-zero (clipping is functional)