diff --git a/blackbirds/models/rama_cont.py b/blackbirds/models/rama_cont.py
index f2406ed..bc5e043 100644
--- a/blackbirds/models/rama_cont.py
+++ b/blackbirds/models/rama_cont.py
@@ -35,7 +35,7 @@ def initialize(self, params):
     def step(self, params, x):
         # draw epsilon_t from normal distribution
         sigma = params[2]
-        epsilon_t = torch.distributions.Normal(0, sigma).rsample((self.n_agents,))
+        epsilon_t = torch.distributions.Normal(0, sigma).rsample()
         # compute order
         nu_t = x[-1, 0, :]
         order = self.compute_order(epsilon_t, nu_t)
diff --git a/requirements.txt b/requirements.txt
index 7747c32..e301890 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 grad-june>=0.1.8
 networkx>=3.0
 normflows>=1.6.2
+numpy==1.26.4
 pyyaml>=6.0
 tensorboard>=2.12.1
 torch>=2.0