diff --git a/src/sand-wedge-data/midpoint.hh b/src/sand-wedge-data/midpoint.hh
new file mode 100644
index 0000000000000000000000000000000000000000..27a2fd4f3da6d6d7d501b117cfc1936835c3dc77
--- /dev/null
+++ b/src/sand-wedge-data/midpoint.hh
@@ -0,0 +1,12 @@
+#ifndef SRC_MIDPOINT_HH
+#define SRC_MIDPOINT_HH
+
+#include <dune/solvers/common/arithmetic.hh>
+
+template <class Vector> Vector midPoint(Vector const &x, Vector const &y) {
+  Vector ret{ 0 };
+  Arithmetic::addProduct(ret, 0.5, x);
+  Arithmetic::addProduct(ret, 0.5, y);
+  return ret;
+}
+#endif
diff --git a/src/sand-wedge-data/mygeometry.hh b/src/sand-wedge-data/mygeometry.hh
index 468175d7ac5965a638b33a063e7a1d2f166fcdb3..d3b122bb7ac321de0d69752caac267e87bfb0264 100644
--- a/src/sand-wedge-data/mygeometry.hh
+++ b/src/sand-wedge-data/mygeometry.hh
@@ -3,14 +3,14 @@
 
 #include <dune/common/fvector.hh>
 
-#include <dune/fufem/arithmetic.hh>
-
 #ifdef HAVE_CAIROMM
 #include <cairomm/context.h>
 #include <cairomm/fontface.h>
 #include <cairomm/surface.h>
 #endif
 
+#include "midpoint.hh"
+
 namespace MyGeometry {
 namespace {
   using LocalVector2D = Dune::FieldVector<double, 2>;
@@ -35,14 +35,6 @@ namespace {
     ret[1][1] = a22;
     return ret;
   }
-
-  LocalVector2D convexCombination(LocalVector2D const &x,
-                                  LocalVector2D const &y) {
-    LocalVector2D ret{ 0 };
-    Arithmetic::addProduct(ret, 0.5, x);
-    Arithmetic::addProduct(ret, 0.5, y);
-    return ret;
-  }
 }
 
 namespace reference {
@@ -67,9 +59,9 @@ namespace reference {
       createVector(B[0] - leftLeg * viscoHeight / rightLeg, B[1] + viscoHeight);
   LocalVector2D const M = createVector(B[0], B[1] + viscoHeight);
 
-  LocalVector2D const G = convexCombination(A, X);
-  LocalVector2D const H = convexCombination(X, Y);
-  LocalVector2D const J = convexCombination(Y, B);
+  LocalVector2D const G = midPoint(A, X);
+  LocalVector2D const H = midPoint(X, Y);
+  LocalVector2D const J = midPoint(Y, B);
 
   LocalVector2D const I = createVector(Y[0] + G[0], Y[1] + G[1]);