diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index 051d38886404cab8edcc5a58736515cad71e6f5b..6e71dfb2ef78aa54691bae8c555570e6bc507d69 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -154,6 +154,16 @@ int main() {
       std::cout << "Number of extremal nodes: " << extremal_nodes << std::endl;
     }
 
+    // TODO: populate on S_F
+    std::vector<double> coefficientOfFriction;
+    coefficientOfFriction.resize(grid.size(grid.maxLevel(), dim));
+    std::fill(coefficientOfFriction.begin(), coefficientOfFriction.end(), 0.0);
+
+    // TODO: populate on S_F
+    std::vector<double> normalStress;
+    normalStress.resize(grid.size(grid.maxLevel(), dim));
+    std::fill(normalStress.begin(), normalStress.end(), 0.0);
+
     { // assemble constant 1-function on Neumann boundary
       BoundaryPatch<GridType::LeafGridView> neumannBoundary(grid.leafView(),
                                                             neumannNodes);