diff --git a/opm/material/eos/PengRobinsonMixture.hpp b/opm/material/eos/PengRobinsonMixture.hpp
index da50fff5b..8a1b63574 100644
--- a/opm/material/eos/PengRobinsonMixture.hpp
+++ b/opm/material/eos/PengRobinsonMixture.hpp
@@ -85,7 +85,6 @@ public:
       * R. Reid, et al.: The Properties of Gases and Liquids,
       * 4th edition, McGraw-Hill, 1987, pp. 42-44, 143-145
       */
-#warning should check why this function is changed
     template <class FluidState, class Params, class LhsEval = typename FluidState::Scalar>
     static LhsEval computeFugacityCoefficient(const FluidState& fs_arg,
                                               const Params& params_arg,
diff --git a/opm/material/eos/PengRobinsonParamsMixture.hpp b/opm/material/eos/PengRobinsonParamsMixture.hpp
index 1f02a12a7..3243d2da8 100644
--- a/opm/material/eos/PengRobinsonParamsMixture.hpp
+++ b/opm/material/eos/PengRobinsonParamsMixture.hpp
@@ -108,12 +108,10 @@ public:
 
             Scalar f_omega;
 
-           // if (useSpe5Relations) {
-                if (omega < 0.49) f_omega = 0.37464  + omega*(1.54226 + omega*(-0.26992));
-                else              f_omega = 0.379642 + omega*(1.48503 + omega*(-0.164423 + omega*0.016666));
-           // }
-           // else
-           //     f_omega = 0.37464 + omega*(1.54226 - omega*0.26992);
+            if (omega < 0.49) 
+                f_omega = 0.37464  + omega*(1.54226 + omega*(-0.26992));
+            else              
+                f_omega = 0.379642 + omega*(1.48503 + omega*(-0.164423 + omega*0.016666));
 
             Valgrind::CheckDefined(f_omega);