diff --git a/inference/interact/fbrs/inference/predictors/brs_functors.py b/inference/interact/fbrs/inference/predictors/brs_functors.py
index 92a5d99..222b61c 100644
--- a/inference/interact/fbrs/inference/predictors/brs_functors.py
+++ b/inference/interact/fbrs/inference/predictors/brs_functors.py
@@ -72,7 +72,7 @@ def __call__(self, x):
         self._last_mask = current_mask
 
         loss.backward()
-        f_grad = opt_params.grad.cpu().numpy().ravel().astype(np.float)
+        f_grad = opt_params.grad.cpu().numpy().ravel().astype(np.cfloat)
 
         return [f_val, f_grad]