diff --git a/src/gui_cond_forecast_preliminary.m b/src/gui_cond_forecast_preliminary.m
index 585a48199eac968e6edf1f3f10647d12ac2a0e0a..a0fdda49d74d37d307765d18d149b16a3674f3de 100644
--- a/src/gui_cond_forecast_preliminary.m
+++ b/src/gui_cond_forecast_preliminary.m
@@ -217,6 +217,10 @@ handles.save_and_go_to_cond_forecast = uicontrol( ...
             gui_tools.show_warning('You must select at least one exogenous variable')
             return
         end
+        if sum([handles.endoTable.Data{:, 1}]) ~= sum([handles.exo_table.Data{:, 1}])
+            gui_tools.show_warning('The number of constrained endogenous variables must be equal to the number of controlled exogenous variables')
+            return
+        end
         model_settings.conditional_forecast_options.controlled_varexo = handles.exo_table.Data([handles.exo_table.Data{:, 1}], 2);
         model_settings.conditional_forecast_options.endo = handles.endoTable.Data([handles.endoTable.Data{:, 1}], 2);
         model_settings.conditional_forecast_options.baseline_file = handles.baseline_file.String;