diff --git a/opm/output/eclipse/RegionCache.hpp b/opm/output/eclipse/RegionCache.hpp
index 9287ebef6..a132e2b6a 100644
--- a/opm/output/eclipse/RegionCache.hpp
+++ b/opm/output/eclipse/RegionCache.hpp
@@ -23,7 +23,6 @@
 #include <vector>
 
 namespace Opm {
-    class Eclipse3DProperties;
     class Schedule;
     class EclipseGrid;
 
@@ -31,7 +30,7 @@ namespace out {
     class RegionCache {
     public:
         RegionCache() = default;
-        RegionCache(const Eclipse3DProperties& properties, const EclipseGrid& grid, const Schedule& schedule);
+        RegionCache(const std::vector<int>& fipnum, const EclipseGrid& grid, const Schedule& schedule);
         const std::vector<std::pair<std::string,size_t>>& connections( int region_id ) const;
 
     private:
diff --git a/src/opm/output/eclipse/RegionCache.cpp b/src/opm/output/eclipse/RegionCache.cpp
index e2f0abedf..f5b14e7ba 100644
--- a/src/opm/output/eclipse/RegionCache.cpp
+++ b/src/opm/output/eclipse/RegionCache.cpp
@@ -30,17 +30,15 @@
 namespace Opm {
 namespace out {
 
-RegionCache::RegionCache(const Eclipse3DProperties& properties, const EclipseGrid& grid, const Schedule& schedule) {
-    const auto& fipnum_data = properties.getIntGridProperty("FIPNUM").getData();
+RegionCache::RegionCache(const std::vector<int>& fipnum, const EclipseGrid& grid, const Schedule& schedule) {
 
     const auto& wells = schedule.getWellsatEnd();
     for (const auto& well : wells) {
         const auto& connections = well.getConnections( );
         for (const auto& c : connections) {
-            size_t global_index = grid.getGlobalIndex( c.getI() , c.getJ() , c.getK());
-            if (grid.cellActive( global_index )) {
-                size_t active_index = grid.activeIndex( global_index );
-                int region_id = fipnum_data[global_index];
+            if (grid.cellActive(c.getI(), c.getJ(), c.getK())) {
+                size_t active_index = grid.activeIndex(c.getI(), c.getJ(), c.getK());
+                int region_id = fipnum[active_index];
                 auto& well_index_list = this->connection_map[ region_id ];
                 well_index_list.push_back( { well.name() , active_index } );
             }
diff --git a/src/opm/output/eclipse/Summary.cpp b/src/opm/output/eclipse/Summary.cpp
index e10ac7b62..3196207a6 100644
--- a/src/opm/output/eclipse/Summary.cpp
+++ b/src/opm/output/eclipse/Summary.cpp
@@ -2052,7 +2052,11 @@ SummaryImplementation(const EclipseState&  es,
                       const Schedule&      sched,
                       const std::string&   basename)
     : grid_          (std::cref(grid))
-    , regCache_      (es.get3DProperties(), grid, sched)
+#ifdef ENABLE_3DPROPS_TESTING
+    , regCache_      (es.get3DProperties().getIntGridProperty("FIPNUM").compressedCopy(grid), grid, sched)
+#else
+    , regCache_      (es.fieldProps().get<int>("FIPNMUM"), grid, sched)
+#endif
     , deferredSMSpec_(makeDeferredSMSpecCreation(es, grid, sched))
     , rset_          (makeResultSet(es.cfg().io(), basename))
     , fmt_           { es.cfg().io().getFMTOUT() }
diff --git a/tests/test_regionCache.cpp b/tests/test_regionCache.cpp
index 506dfe4c5..ae177ae57 100644
--- a/tests/test_regionCache.cpp
+++ b/tests/test_regionCache.cpp
@@ -44,7 +44,7 @@ BOOST_AUTO_TEST_CASE(create) {
     EclipseState es(deck);
     const EclipseGrid& grid = es.getInputGrid();
     Schedule schedule( deck, es);
-    out::RegionCache rc(es.get3DProperties() , grid, schedule);
+    out::RegionCache rc(es.get3DProperties().getIntGridProperty("FIPNUM").compressedCopy(grid) , grid, schedule);
 
     {
         const auto& empty = rc.connections( 4 );