diff --git a/sharkfin/simulation.py b/sharkfin/simulation.py
index ddff5e4..adab5ff 100644
--- a/sharkfin/simulation.py
+++ b/sharkfin/simulation.py
@@ -766,13 +766,13 @@ def __init__(
             fm_args=fm_args,
         )
 
-        self.rng = rng if rng is not None else np.random.default_rng()
-
         if seed:
             self.seed = seed
         elif hasattr(rng, "seed"):
             self.seed = rng.seed
 
+        self.rng = rng if rng is not None else np.random.default_rng(seed)
+
         # TODO: Make this more variable.
         if a is not None:
             self.attention_rate = a
diff --git a/simulate/run_any_simulation.py b/simulate/run_any_simulation.py
index 8bdbf2a..1350a0e 100644
--- a/simulate/run_any_simulation.py
+++ b/simulate/run_any_simulation.py
@@ -379,6 +379,8 @@ def env_param(name, default):
         parameter_dict["aNrmInitMean"] = pop_aNrmInitMean
     else:
         raise Exception(f"No valid population named! Got {population_name}. Panic!")
+    
+    bigseed = rng.integers(0, 2**31 - 1)
 
     if args.simulation == "Attention":
         data, sim_stats, history, class_stats = run_attention_simulation(
@@ -398,7 +400,7 @@ def env_param(name, default):
             mba=mba,
             rng=rng,
             pad=pad,
-            seed=seed,
+            seed=bigseed,
         )
     elif args.simulation == "Calibration":
         data, sim_stats, history, class_stats = run_chum_simulation(
@@ -412,7 +414,7 @@ def env_param(name, default):
             buy=buysize,
             sell=sellsize,
             pad=pad,
-            seed=seed,
+            seed=bigseed,
         )
     else:
         print(