diff --git a/test/porousmediumflow/mpnc/implicit/combustionproblem1c.hh b/test/porousmediumflow/mpnc/implicit/combustionproblem1c.hh
index 9776ca5b2d1f0a65746f815cc2e0e56db5cf2eb8..f716e4de722b0c229e86a4dadd9851c82917c93d 100644
--- a/test/porousmediumflow/mpnc/implicit/combustionproblem1c.hh
+++ b/test/porousmediumflow/mpnc/implicit/combustionproblem1c.hh
@@ -333,6 +333,10 @@ public:
                 dummyCache,
                 wPhaseIdx);
         fluidState.setDensity(wPhaseIdx, density);
+        const Scalar molarDensity = FluidSystem::molarDensity(fluidState,
+                dummyCache,
+                wPhaseIdx);
+        fluidState.setMolarDensity(wPhaseIdx, molarDensity);
 
         for(int phaseIdx=0; phaseIdx<numPhases; phaseIdx++) {
             const Scalar h = FluidSystem::enthalpy(fluidState,
diff --git a/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh b/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh
index 43f7dcec1e98cd61c290739db157d40c0286b1d2..84df600d6d92639cdb0f5044b35236f627949319 100644
--- a/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh
+++ b/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh
@@ -333,9 +333,13 @@ public:
 
         // compute density of injection phase
         const Scalar density = FluidSystem::density(fluidState,
-                                                     dummyCache,
-                                                     gasPhaseIdx);
+                                                    dummyCache,
+                                                    gasPhaseIdx);
         fluidState.setDensity(gasPhaseIdx, density);
+        const Scalar molarDensity = FluidSystem::molarDensity(fluidState,
+                                                              dummyCache,
+                                                              gasPhaseIdx);
+        fluidState.setMolarDensity(gasPhaseIdx, molarDensity);
 
         for(int phaseIdx=0; phaseIdx<numPhases; phaseIdx++)
         {