diff --git a/Formation/OTRERA_formation/Models/Test_Media.mo b/Formation/OTRERA_formation/Models/Test_Media.mo
index c0a9ea0..4437d82 100644
--- a/Formation/OTRERA_formation/Models/Test_Media.mo
+++ b/Formation/OTRERA_formation/Models/Test_Media.mo
@@ -8,7 +8,7 @@ model Test_Media
   parameter Modelica.Units.SI.Pressure p = 155e5 ;
   //INTERNAL VARIABLES
   Medium.ThermodynamicState state ;
-  Modelica.Units.SI.Density d ;
+  Medium.Density d ;
   
   //IMPORTED COMPONENTS