diff --git a/src/layers/fc_layer.rs b/src/layers/fc_layer.rs
index 8f4da68..0728a84 100644
--- a/src/layers/fc_layer.rs
+++ b/src/layers/fc_layer.rs
@@ -85,13 +85,17 @@ impl Layer for FCLayer {
 
     fn backward_pass(&mut self, output_error: Array1<f64>, learning_rate: f64) -> Array1<f64> {
         let input_error = output_error.dot(&self.weights.t());
-        let delta_weights = self
+        let mut delta_weights = self
             .input
             .to_shape((self.input.len(), 1usize))
             .unwrap()
             .dot(&output_error.to_shape((1usize, output_error.len())).unwrap());
-        self.weights = &self.weights + learning_rate * &delta_weights;
-        self.biases = &self.biases + learning_rate * &output_error;
+        delta_weights *= learning_rate;
+        let delta_biases = output_error * learning_rate;
+
+        self.weights += &delta_weights;
+        self.biases += &delta_biases;
+
         input_error
     }
 }