diff --git a/ProcessLib/BoundaryCondition/BoundaryCondition.cpp b/ProcessLib/BoundaryCondition/BoundaryCondition.cpp
index eb182112a80be3da6d8b54e6f7da699ce0d0f6bb..65ce716963ab88aa94e01528dec4966cacfc9777 100644
--- a/ProcessLib/BoundaryCondition/BoundaryCondition.cpp
+++ b/ProcessLib/BoundaryCondition/BoundaryCondition.cpp
@@ -15,7 +15,7 @@
 #include "UniformNeumannBoundaryCondition.h"
 #include "UniformRobinBoundaryCondition.h"
 
-std::vector<MeshLib::Element*> getClonedElements(
+static std::vector<MeshLib::Element*> getClonedElements(
     MeshGeoToolsLib::BoundaryElementsSearcher& boundary_element_searcher,
     GeoLib::GeoObject const& geometry)
 {