diff --git a/crates/ml/tests/smoke_test_real_data.rs b/crates/ml/tests/smoke_test_real_data.rs
index a63004b04..a04af75ec 100644
--- a/crates/ml/tests/smoke_test_real_data.rs
+++ b/crates/ml/tests/smoke_test_real_data.rs
@@ -709,7 +709,11 @@ mod gpu_smoke {
             episode_length: timesteps,
             epsilon: 0.0, // NoisyNets handle exploration
             gamma: 0.99,
-            noisy_sigma_init: 0.5,
+            // sigma must be large enough that NoisyNet noise dominates Q-value gaps
+            // even on wide networks (256-dim). With random Xavier init on a 256-wide
+            // network, Q-values are O(1/sqrt(256)) ≈ 0.06 apart. sigma=2.0 ensures
+            // noise O(sigma/sqrt(fan_in)) ≈ 0.12 exceeds this gap.
+            noisy_sigma_init: 2.0,
             num_atoms: 51,
             v_min: -10.0,
             v_max: 10.0,