diff --git a/src/cnn/cnn.c b/src/cnn/cnn.c
index 6e300f0..8216fac 100644
--- a/src/cnn/cnn.c
+++ b/src/cnn/cnn.c
@@ -249,14 +249,15 @@ void backward_propagation(Network* network, int wanted_number) {
         int output_depth = network->depth[i+1];
         int output_width = network->width[i+1];
 
-        int activation = i==0?SIGMOID:network->kernel[i-1]->activation;
+        int is_last_layer = i==0;
+        int activation = is_last_layer?SIGMOID:network->kernel[i-1]->activation;
 
 
         if (k_i->cnn) { // Convolution
-            backward_convolution(k_i->cnn, input, input_z, output, input_depth, input_width, output_depth, output_width, -activation, i==0);
+            backward_convolution(k_i->cnn, input, input_z, output, input_depth, input_width, output_depth, output_width, -activation, is_last_layer);
         } else if (k_i->nn) { // Full connection
             if (k_i->linearisation == DOESNT_LINEARISE) { // Vecteur -> Vecteur
-                backward_dense(k_i->nn, input[0][0], input_z[0][0], output[0][0], input_width, output_width, -activation, i==0);
+                backward_dense(k_i->nn, input[0][0], input_z[0][0], output[0][0], input_width, output_width, -activation, is_last_layer);
             } else { // Matrice -> vecteur
                 backward_linearisation(k_i->nn, input, input_z, output[0][0], input_depth, input_width, output_width, -activation);
             }