diff --git a/power_grid_model_c/power_grid_model/include/power_grid_model/math_solver/observability.hpp b/power_grid_model_c/power_grid_model/include/power_grid_model/math_solver/observability.hpp
index cac259601..62a845ada 100644
--- a/power_grid_model_c/power_grid_model/include/power_grid_model/math_solver/observability.hpp
+++ b/power_grid_model_c/power_grid_model/include/power_grid_model/math_solver/observability.hpp
@@ -132,7 +132,7 @@ inline void necessary_observability_check(MeasuredValues<sym> const& measured_va
         // count flow sensors again
         Idx const n_flow_sensor_new = std::reduce(flow_sensors.cbegin(), flow_sensors.cend(), Idx{}, std::plus<Idx>{});
         if (n_flow_sensor_new < n_bus - 1) {
-            throw NotObservableError{"The number of power sensors seems to be sufficient, but they are not independent "
+            throw NotObservableError{"The number of power sensors appears sufficient, but they are not independent "
                                      "enough. The system is still not observable.\n"};
         }
     }