diff --git a/source/Rbm.cpp b/source/Rbm.cpp
index e49d4c0..f8185f8 100644
--- a/source/Rbm.cpp
+++ b/source/Rbm.cpp
@@ -11,6 +11,7 @@
  * Created on 21. Oktober 2019, 21:28
  */
 
+#include <cassert>
 #include "Rbm.hpp"
 
 Rbm::Rbm(size_t numVisible, size_t numHidden)
@@ -19,6 +20,8 @@ Rbm::Rbm(size_t numVisible, size_t numHidden)
 , m_bv(1, numVisible)
 , m_bh(1, numHidden)
 {
+	assert(numVisible > 0);
+	assert(numHidden > 0);
 	Noise_Init(&m_noise, 0x32727155);
 }
 
diff --git a/source/main.cpp b/source/main.cpp
index 12e35cb..475ca66 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -90,11 +90,12 @@ int main()
 	printf("Loaded %d training samples\n", (int)numTraining);
 
 #if 0
+	const int numLayers = 4;
 	int i = 0;
 	Layer *lowerLayer = new Layer("Layer", i, 16, 16, 8);
 	stack.addLayer(lowerLayer);
 	
-	for (++i; i < 4; i++)
+	for (++i; i < numLayers; i++)
 	{
 		Layer *layer = new Layer("Layer", i, lowerLayer->bh().n_elem, 1, lowerLayer->bh().n_elem >> 1);
 		layer->params().learningRate = lowerLayer->params().learningRate/2;