diff --git a/ProcessLib/HeatTransportBHE/BHE/BHE_1U.h b/ProcessLib/HeatTransportBHE/BHE/BHE_1U.h
index 0063864dce70d4ae2547c45321ea5f5d21ad8c8f..482fbeae0587291d9bef7b63fe309573a118d35a 100644
--- a/ProcessLib/HeatTransportBHE/BHE/BHE_1U.h
+++ b/ProcessLib/HeatTransportBHE/BHE/BHE_1U.h
@@ -140,8 +140,8 @@ private:
 
 public:
     std::array<double, number_of_unknowns> const cross_section_areas = {
-        {_pipes.inlet.area(), _pipes.inlet.area(),
-         borehole_geometry.area() / 2 - _pipes.outlet.area(),
+        {_pipes.inlet.area(), _pipes.outlet.area(),
+         borehole_geometry.area() / 2 - _pipes.inlet.area(),
          borehole_geometry.area() / 2 - _pipes.outlet.area()}};
 
 private: