diff --git a/tools/machine-learning/mujoco/packages/nao_env/src/nao_env/nao_base_env.py b/tools/machine-learning/mujoco/packages/nao_env/src/nao_env/nao_base_env.py
index 7f2b82ccdc..b90d4ee6be 100644
--- a/tools/machine-learning/mujoco/packages/nao_env/src/nao_env/nao_base_env.py
+++ b/tools/machine-learning/mujoco/packages/nao_env/src/nao_env/nao_base_env.py
@@ -147,5 +147,5 @@ def do_simulation(
         ctrl: NDArray[np.floating],
         n_frames: int,
     ) -> None:
-        self.data.ctrl[self._actuation_mask] += ctrl
+        self.data.ctrl[self._actuation_mask] = ctrl
         self._step_mujoco_simulation(self.data.ctrl, n_frames)