diff --git a/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h b/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h
index 0fabb9d555b6a46554e0a04870b8b2954e0a5066..0ed66f13587a78af296dbb9dc138afe8fccbc9f0 100644
--- a/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h
+++ b/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h
@@ -15,6 +15,7 @@
 
 #include "MaterialLib/SolidModels/KelvinVector.h"
 #include "NumLib/Function/Interpolation.h"
+#include "ProcessLib/CoupledSolutionsForStaggeredScheme.h"
 
 namespace ProcessLib
 {