diff --git a/ApplicationLibCode/ReservoirDataModel/RigActiveCellGrid.h b/ApplicationLibCode/ReservoirDataModel/RigActiveCellGrid.h
index 47ba91ee2a..142b47e822 100644
--- a/ApplicationLibCode/ReservoirDataModel/RigActiveCellGrid.h
+++ b/ApplicationLibCode/ReservoirDataModel/RigActiveCellGrid.h
@@ -34,7 +34,8 @@ public:
     size_t totalCellCount() const override;
     size_t totalActiveCellCount() const;
 
-public: // only for use by file readers!
+protected: // only for use by file readers!
+    friend class RifReaderOpmCommonActive;
     std::map<size_t, RigCell>&       nativeCells();
     const std::map<size_t, RigCell>& nativeCells() const;
     void                             setTotalCellCount( size_t totalCellCount );
diff --git a/ApplicationLibCode/ReservoirDataModel/RigMainGrid.h b/ApplicationLibCode/ReservoirDataModel/RigMainGrid.h
index 88ac93e79f..a4e98184a3 100644
--- a/ApplicationLibCode/ReservoirDataModel/RigMainGrid.h
+++ b/ApplicationLibCode/ReservoirDataModel/RigMainGrid.h
@@ -113,7 +113,16 @@ public:
     bool isDualPorosity() const;
     void setDualPorosity( bool enable );
 
-public: // only for use by file readers!
+protected: // only for use by file readers and internal services. TODO: replace with a better API
+    friend class RigGridBase;
+    friend class RigReservoirBuilder;
+    friend class RifRoffFileTools;
+    friend class RifEclipseOutputFileTools;
+    friend class RifReaderEclipseOutput;
+    friend class RifReaderOpmCommon;
+    friend class RiaGrpcCaseService;
+    friend class RiaActiveCellInfoStateHandler;
+    friend class RicCreateTemporaryLgrFeature;
     std::vector<RigCell>&       reservoirCells();
     const std::vector<RigCell>& reservoirCells() const;