diff --git a/src/imitation/scripts/config/tuning.py b/src/imitation/scripts/config/tuning.py
index 2db1d6f08..daed7c1a0 100644
--- a/src/imitation/scripts/config/tuning.py
+++ b/src/imitation/scripts/config/tuning.py
@@ -201,7 +201,7 @@ def pc():
                 "active_selection_oversampling": tune.randint(1, 11),
                 "comparison_queue_size": tune.randint(1, 1001),  # upper bound determined by total_comparisons=1000
                 "exploration_frac": tune.uniform(0.0, 0.5),
-                "fragment_length": 100,  # TODO: tune this too!
+                "fragment_length": tune.randint(1, 1001),  # trajectories are 1000 steps long
                 "gatherer_kwargs": {
                     "temperature": tune.uniform(0.0, 2.0),
                     "discount_factor": tune.uniform(0.95, 1.0),