diff --git a/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.cpp b/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.cpp
index 7139f9d7cbe214749c043f501adcd9b25b9446c2..602029b565ddafc4a207f11f0861397dfcf9964c 100644
--- a/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.cpp
+++ b/ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.cpp
@@ -9,6 +9,7 @@
 
 #include "CreateGroundwaterFlowProcess.h"
 
+#include "BaseLib/FileTools.h"
 #include "ProcessLib/Utils/ParseSecondaryVariables.h"
 #include "ProcessLib/Utils/ProcessUtils.h"
 #include "ProcessLib/CalculateSurfaceFlux/ParseCalculateSurfaceFluxData.h"