diff --git a/notebooks/3_NeuralNetworks/neural_network_raw.ipynb b/notebooks/3_NeuralNetworks/neural_network_raw.ipynb
index 6d9dbd24..d7a50ecd 100644
--- a/notebooks/3_NeuralNetworks/neural_network_raw.ipynb
+++ b/notebooks/3_NeuralNetworks/neural_network_raw.ipynb
@@ -117,8 +117,10 @@
     "def neural_net(x):\n",
     "    # Hidden fully connected layer with 256 neurons\n",
     "    layer_1 = tf.add(tf.matmul(x, weights['h1']), biases['b1'])\n",
+    "    layer_1 = tf.nn.sigmoid(layer_1)",
     "    # Hidden fully connected layer with 256 neurons\n",
     "    layer_2 = tf.add(tf.matmul(layer_1, weights['h2']), biases['b2'])\n",
+    "    layer_2 = tf.nn.sigmoid(layer_2)",
     "    # Output fully connected layer with a neuron for each class\n",
     "    out_layer = tf.matmul(layer_2, weights['out']) + biases['out']\n",
     "    return out_layer"