diff --git a/Net.cpp b/Net.cpp
index fbbda5b..9119e4a 100644
--- a/Net.cpp
+++ b/Net.cpp
@@ -87,12 +87,12 @@ void Net::backProp(const std::vector<double> &targetValues)
 	}
 
 	// calculate hidden neuron gradients
-	for (auto it = end() - 1; it != begin(); --it)
+	for (auto it = end() - 1; (it - 1) != begin(); --it)
 	{
 		Layer &hiddenLayer = *(it - 1);
 		Layer &nextLayer = *it;
 
-		for (auto neuron : hiddenLayer)
+		for (Neuron &neuron : hiddenLayer)
 		{
 			neuron.calcHiddenGradients(nextLayer);
 		}
diff --git a/Neuron.cpp b/Neuron.cpp
index 29aebb4..e57782e 100644
--- a/Neuron.cpp
+++ b/Neuron.cpp
@@ -65,7 +65,7 @@ double Neuron::sumDOW(const Layer & nextLayer) const
 {
 	double sum = 0;
 
-	for (size_t i = 0; i < nextLayer.size() - 1; ++i)
+	for (size_t i = 0; i < outputWeights.size(); ++i)
 	{
 		sum += outputWeights[i] * nextLayer[i].getGradient();
 	}