diff --git a/opm/simulators/wells/BlackoilWellModel.hpp b/opm/simulators/wells/BlackoilWellModel.hpp
index 1e48a63fc..abe10bee4 100644
--- a/opm/simulators/wells/BlackoilWellModel.hpp
+++ b/opm/simulators/wells/BlackoilWellModel.hpp
@@ -425,14 +425,6 @@ template<class Scalar> class WellContributions;
             std::unique_ptr<RateConverterType> rateConverter_{};
             std::map<std::string, std::unique_ptr<AverageRegionalPressureType>> regionalAveragePressureCalculator_{};
 
-            struct WBPCalcID
-            {
-                std::optional<typename std::vector<WellInterfacePtr>::size_type> openWellIdx_{};
-                std::size_t wbpCalcIdx_{};
-            };
-
-            std::vector<WBPCalcID> wbpCalcMap_{};
-
             SimulatorReportSingle last_report_{};
 
             // Pre-step network solve at static reservoir conditions (group and well states might be updated)
diff --git a/opm/simulators/wells/BlackoilWellModelGeneric.hpp b/opm/simulators/wells/BlackoilWellModelGeneric.hpp
index b4021786f..116bed1fe 100644
--- a/opm/simulators/wells/BlackoilWellModelGeneric.hpp
+++ b/opm/simulators/wells/BlackoilWellModelGeneric.hpp
@@ -581,6 +581,14 @@ protected:
     std::vector<WellProdIndexCalculator<Scalar>> prod_index_calc_;
     mutable ParallelWBPCalculation<Scalar> wbpCalculationService_;
 
+    struct WBPCalcID
+    {
+        std::optional<typename std::vector<WellInterfaceGeneric<Scalar>*>::size_type> openWellIdx_{};
+        std::size_t wbpCalcIdx_{};
+    };
+
+    std::vector<WBPCalcID> wbpCalcMap_{};
+
     std::vector<int> pvt_region_idx_;
 
     mutable std::unordered_set<std::string> closed_this_step_;