diff --git a/lessons/3-NeuralNetworks/03-Perceptron/Perceptron.ipynb b/lessons/3-NeuralNetworks/03-Perceptron/Perceptron.ipynb
index 6df73e93..2928fa0a 100644
--- a/lessons/3-NeuralNetworks/03-Perceptron/Perceptron.ipynb
+++ b/lessons/3-NeuralNetworks/03-Perceptron/Perceptron.ipynb
@@ -462,7 +462,8 @@
     "            neg_out = np.dot(negative_examples, weights)        \n",
     "            pos_correct = (pos_out >= 0).sum() / float(pos_count)\n",
     "            neg_correct = (neg_out < 0).sum() / float(neg_count)\n",
-    "            snapshots.append((np.copy(weights),(pos_correct+neg_correct)/2.0))\n",
+    "            # make correction a list so it is homogeneous to weights list then numpy array accepts\n",
+    "            snapshots.append((np.concatenate(weights),[(pos_correct+neg_correct)/2.0,0,0]))\n",
     "\n",
     "    return np.array(snapshots)\n",
     "\n",
@@ -476,7 +477,7 @@
     "    pylab.plot(np.arange(len(snapshots[:,1])), snapshots[:,1])\n",
     "    pylab.ylabel('Accuracy')\n",
     "    pylab.xlabel('Iteration')\n",
-    "    pylab.plot(step, snapshots[step,1], \"bo\")\n",
+    "    pylab.plot(step, snapshots[step,1][0], \"bo\")\n",
     "    pylab.show()\n",
     "def pl1(step): plotit(pos_examples,neg_examples,snapshots,step)"
    ]