diff --git a/NumLib/DOF/LocalToGlobalIndexMap.cpp b/NumLib/DOF/LocalToGlobalIndexMap.cpp
index c9fb761692c6b7988fbfc535a78bc5a3d3e54763..100cb8402f3430ee54db9b30a87933b203bd4a85 100644
--- a/NumLib/DOF/LocalToGlobalIndexMap.cpp
+++ b/NumLib/DOF/LocalToGlobalIndexMap.cpp
@@ -10,6 +10,7 @@
 #include "LocalToGlobalIndexMap.h"
 
 #include <algorithm>
+#include <numeric>
 #include <unordered_set>
 
 namespace NumLib
diff --git a/ProcessLib/BoundaryCondition/NormalTractionBoundaryCondition-impl.h b/ProcessLib/BoundaryCondition/NormalTractionBoundaryCondition-impl.h
index 36fcc35df04623e7db7196bebcb1ac73581e16af..fc0145570e4c9eefe4a584123a45e6e9c3a751c0 100644
--- a/ProcessLib/BoundaryCondition/NormalTractionBoundaryCondition-impl.h
+++ b/ProcessLib/BoundaryCondition/NormalTractionBoundaryCondition-impl.h
@@ -10,6 +10,8 @@
 
 #pragma once
 
+#include <numeric>
+
 #include "MeshLib/MeshSearch/NodeSearch.h"
 #include "ProcessLib/Utils/CreateLocalAssemblers.h"
 #include "ProcessLib/Utils/ProcessUtils.h"