diff --git a/opm/parser/eclipse/EclipseState/InitConfig/Equil.hpp b/opm/parser/eclipse/EclipseState/InitConfig/Equil.hpp
index 9c9f6ccf6..804383334 100644
--- a/opm/parser/eclipse/EclipseState/InitConfig/Equil.hpp
+++ b/opm/parser/eclipse/EclipseState/InitConfig/Equil.hpp
@@ -1,6 +1,8 @@
 #ifndef OPM_EQUIL_HPP
 #define OPM_EQUIL_HPP
 
+#include <vector>
+
 namespace Opm {
 
     class DeckKeyword;