diff --git a/opm/models/blackoil/blackoilmodel.hh b/opm/models/blackoil/blackoilmodel.hh
index cd766a2b8..ac1e41253 100644
--- a/opm/models/blackoil/blackoilmodel.hh
+++ b/opm/models/blackoil/blackoilmodel.hh
@@ -326,9 +326,7 @@ public:
         // register runtime parameters of the VTK output modules
         VtkBlackOilModule<TypeTag>::registerParameters();
         VtkCompositionModule<TypeTag>::registerParameters();
-
-        if constexpr (enableDiffusion)
-            VtkDiffusionModule<TypeTag>::registerParameters();
+        VtkDiffusionModule<TypeTag>::registerParameters();
     }
 
     /*!