diff --git a/dumux/porousmediumflow/mpnc/iofields.hh b/dumux/porousmediumflow/mpnc/iofields.hh
index 7a51660f407f7d41d5bab318c3c2e52994030650..ee9d59c61a40a7a2cd2a03de779bb0739529cccc 100644
--- a/dumux/porousmediumflow/mpnc/iofields.hh
+++ b/dumux/porousmediumflow/mpnc/iofields.hh
@@ -57,6 +57,11 @@ public:
                                       IOName::moleFraction<FluidSystem>(i, j));
         }
 
+        for (int j = 0; j < VolumeVariables::numComponents(); ++j)
+        out.addVolumeVariable([j](const auto& v){ return v.fugacity(j); },
+                              "fugacity^"+ FluidSystem::componentName(j));
+
+
         out.addVolumeVariable([](const auto& v){ return v.porosity(); },
                               IOName::porosity());
     }