diff --git a/src/gromacs/applied_forces/densityfitting/densityfitting.cpp b/src/gromacs/applied_forces/densityfitting/densityfitting.cpp
index b5d10ea80d0a4f3befb8b6d21ed70ea9799bfe2c..bf578357c131e75a608e0137134a4ae28078c00f 100644
--- a/src/gromacs/applied_forces/densityfitting/densityfitting.cpp
+++ b/src/gromacs/applied_forces/densityfitting/densityfitting.cpp
@@ -53,6 +53,7 @@
 #include "gromacs/math/coordinatetransformation.h"
 #include "gromacs/math/multidimarray.h"
 #include "gromacs/mdtypes/imdmodule.h"
+#include "gromacs/selection/indexutil.h"
 #include "gromacs/utility/classhelpers.h"
 #include "gromacs/utility/exceptions.h"
 #include "gromacs/utility/keyvaluetreebuilder.h"