diff --git a/dumux/material/components/iapws/region2.hh b/dumux/material/components/iapws/region2.hh
index 32c53092f7c19cf57ca7901c216b1f593794c13d..160e0bc32f953c96b257c27078c10213c9973dac 100644
--- a/dumux/material/components/iapws/region2.hh
+++ b/dumux/material/components/iapws/region2.hh
@@ -323,8 +323,8 @@ public:
                 n_r(i) *
                 std::pow(pi_,  I_r(i)) *
                 J_r(i) *
-                (J_g(i) - 1) *
-                std::pow(tau_ - 0.5, J_r(i) - 2);
+                (J_r(i) - 1.) *
+                std::pow(tau_ - 0.5, J_r(i) - 2.);
         }
 
         return result;