diff --git a/DDRec/src/LayeringExtensionImpl.cpp b/DDRec/src/LayeringExtensionImpl.cpp
index e2cef63fb502a7085b7687c80388a218a573038e..e251b55b4a37b0cf28b106875020908cd581d270 100644
--- a/DDRec/src/LayeringExtensionImpl.cpp
+++ b/DDRec/src/LayeringExtensionImpl.cpp
@@ -171,7 +171,9 @@ void LayeringExtensionImpl::checkMap(int layerIndex) const {
 	map<int, LayerAttributes>::iterator it;
 	it = _layerMap.find(layerIndex);
 	if (it == _layerMap.end()) {
-		// TODO throw exception
+	  std::stringstream err;
+	  err << "No entry found for layer" << layerIndex;
+	  throw std::out_of_range(err.str());
 	}
 	if (not it->second.isCalculated) {
 		it->second.calculate();