diff --git a/test/material/fluidmatrixinteractions/2p/thermalconductivityspatialparams.hh b/test/material/fluidmatrixinteractions/2p/thermalconductivityspatialparams.hh
index 46452b12e1fa08e913c7cd1341c4d94ecfac197b..55701dc5a6cb1e2de4cb44616ab6790ca5661cb4 100644
--- a/test/material/fluidmatrixinteractions/2p/thermalconductivityspatialparams.hh
+++ b/test/material/fluidmatrixinteractions/2p/thermalconductivityspatialparams.hh
@@ -54,7 +54,7 @@ public:
         PlotThermalConductivityModel<TypeTag> plotThermalConductivityModel_(293.15, 1e5);
         std::string fileName = GET_RUNTIME_PARAM_FROM_GROUP(TypeTag, std::string, Output, File);
         plotThermalConductivityModel_.addlambdaeffcurve(gnuplot, this->porosity_, this->rhoSolid_, this->lambdaSolid_,
-                                                        0.0, 1.0, fileName);
+                                                        0.0, 1.0, fileName + ".dat");
         gnuplot.plot("lambda_eff");
     }
 };
diff --git a/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh b/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh
index df742981f5712a74ce64801b68eda9941652d16c..476e31f0ac608dc552f9e461befc47a92b621d72 100644
--- a/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh
+++ b/test/porousmediumflow/mpnc/implicit/evaporationatmosphereproblem.hh
@@ -352,7 +352,7 @@ public:
         gnuplot_.setOption("set label 'at time " + stream.str() + "' at screen 0.15,0.90 left");
         gnuplot_.setDatafileSeparator(' ');
         std::string fileName = outputName_ + "plotOverLineIntoDepth.dat";
-        gnuplot_.addFileToPlot(fileName, fileName, " u 11:4 w l");
+        gnuplot_.addFileToPlot(fileName, "u 11:4 w l");
         gnuplot_.plot("plot");
     }