diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index 830939b5d6f70b81744971f64b0a712ffb889868..4f7359d51bfbb588dd31c7ec87714abd5c675023 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -158,17 +158,19 @@ int main() {
       BoundaryPatch<GridType::LeafGridView> neumannBoundary(grid.leafView(),
                                                             neumannNodes);
 
-      std::vector<Dune::FieldVector<double, 1>> b;
-      ConstantFunction<SmallVector, Dune::FieldVector<double, 1>>
-      constantOneFunction(1);
-      NeumannBoundaryAssembler<GridType, Dune::FieldVector<double, 1>>
-      neumannBoundaryAssembler(constantOneFunction);
-
-      BoundaryFunctionalAssembler<P1Basis> boundaryFunctionalAssembler(
-          p1Basis, neumannBoundary);
-      boundaryFunctionalAssembler.assemble(
-          neumannBoundaryAssembler, b,
-          true); // resize the output vector and zero all of its entries
+      { // constant 1D function
+        std::vector<Dune::FieldVector<double, 1>> b;
+        ConstantFunction<SmallVector, Dune::FieldVector<double, 1>>
+        constantOneFunction(1);
+        NeumannBoundaryAssembler<GridType, Dune::FieldVector<double, 1>>
+        neumannBoundaryAssembler(constantOneFunction);
+
+        BoundaryFunctionalAssembler<P1Basis> boundaryFunctionalAssembler(
+            p1Basis, neumannBoundary);
+        boundaryFunctionalAssembler.assemble(
+            neumannBoundaryAssembler, b,
+            true); // resize the output vector and zero all of its entries
+      }
     }
 
     { // experiment with convex problems and the like