diff --git a/src/layers/activation_layer.rs b/src/layers/activation_layer.rs
index 8aa53cf..8a271ed 100644
--- a/src/layers/activation_layer.rs
+++ b/src/layers/activation_layer.rs
@@ -30,8 +30,6 @@ impl Layer for ActivationLayer {
     }
 
     fn backward_pass(&mut self, output_error: ArrayView1<f64>, _learning_rate: f64) -> Array1<f64> {
-        let mut temp = (self.activation_prime)(&self.input);
-        temp.zip_mut_with(&output_error, |x, y| *x *= y);
-        temp
+        (self.activation_prime)(&self.input) * output_error
     }
 }