diff --git a/opm/core/fluid/BlackoilPropertiesBasic.cpp b/opm/core/fluid/BlackoilPropertiesBasic.cpp
index ce6b5ae55..ac12b2004 100644
--- a/opm/core/fluid/BlackoilPropertiesBasic.cpp
+++ b/opm/core/fluid/BlackoilPropertiesBasic.cpp
@@ -32,7 +32,7 @@ namespace Opm
 	double poro = param.getDefault("porosity", 1.0);
 	using namespace Opm::unit;
 	using namespace Opm::prefix;
-	double perm = param.getDefault("permeability", 100)*milli*darcy;
+	double perm = param.getDefault("permeability", 100.0)*milli*darcy;
         rock_.init(dim, num_cells, poro, perm);
 	pvt_.init(param);
         satprops_.init(param);
diff --git a/opm/core/fluid/IncompPropertiesBasic.cpp b/opm/core/fluid/IncompPropertiesBasic.cpp
index 572f5fcb5..ddcd07519 100644
--- a/opm/core/fluid/IncompPropertiesBasic.cpp
+++ b/opm/core/fluid/IncompPropertiesBasic.cpp
@@ -34,7 +34,7 @@ namespace Opm
 	double poro = param.getDefault("porosity", 1.0);
 	using namespace Opm::unit;
 	using namespace Opm::prefix;
-	double perm = param.getDefault("permeability", 100)*milli*darcy;
+	double perm = param.getDefault("permeability", 100.0)*milli*darcy;
         rock_.init(dim, num_cells, poro, perm);
 	pvt_.init(param);
         satprops_.init(param);