diff --git a/feedforward neural network/model/inc/ffNet.h b/feedforward neural network/model/inc/ffNet.h
index 4d1855d36b20539a639b07822ce592210799cc40..dc63f8a6aa875cb2d4eaa47a734717797c606c9a 100644
--- a/feedforward neural network/model/inc/ffNet.h	
+++ b/feedforward neural network/model/inc/ffNet.h	
@@ -283,7 +283,7 @@ namespace melon {
     // Get the number of internal network variables
     template <typename T>
     unsigned int FeedForwardNet<T>::get_number_of_full_space_variables() {
-        if (!_modelLoaded) {
+        if (!MelonModel<T>::_modelLoaded) {
             throw MelonException("  Error: No network loaded.");
         }
 
@@ -301,7 +301,7 @@ namespace melon {
     // Returns the number and the names of the internal variables of the network
     template <typename T>
     void FeedForwardNet<T>::get_full_space_variables(unsigned int& variableNumber, std::vector<std::string>& variableNames, std::vector<std::pair<double, double>>& variableBounds) {
-        if (!_modelLoaded) {
+        if (!MelonModel<T>::_modelLoaded) {
             throw MelonException("  Error: No network loaded.");
         }
 
@@ -355,7 +355,7 @@ namespace melon {
     // Calculates the prediction of the feed forward net for a given point
     template <typename T>
     std::vector<T> FeedForwardNet<T>::_calculate_prediction(const std::vector<T> input, const std::vector<T> internalVariables, const bool fullSpace, std::vector<T>& constraints) {
-        if (_modelLoaded) {
+        if (MelonModel<T>::_modelLoaded) {
             // ---------------------------------------------------------------------------------
             // 0: Initialization
             // ---------------------------------------------------------------------------------