diff --git a/src/TurbulenceModels/phaseCompressible/LES/Niceno/NicenoKEqn.C b/src/TurbulenceModels/phaseCompressible/LES/Niceno/NicenoKEqn.C
index 3cddd50af5..e35ad01340 100644
--- a/src/TurbulenceModels/phaseCompressible/LES/Niceno/NicenoKEqn.C
+++ b/src/TurbulenceModels/phaseCompressible/LES/Niceno/NicenoKEqn.C
@@ -134,7 +134,8 @@ NicenoKEqn<BasicTurbulenceModel>::gasTurbulence() const
         const volVectorField& U = this->U_;
 
         const transportModel& liquid = this->transport();
-        const twoPhaseSystem& fluid = liquid.fluid();
+        const twoPhaseSystem& fluid =
+            refCast<const twoPhaseSystem>(liquid.fluid());
         const transportModel& gas = fluid.otherPhase(liquid);
 
         gasTurbulencePtr_ =
@@ -175,7 +176,8 @@ tmp<volScalarField> NicenoKEqn<BasicTurbulenceModel>::bubbleG() const
         this->gasTurbulence();
 
     const transportModel& liquid = this->transport();
-    const twoPhaseSystem& fluid = liquid.fluid();
+    const twoPhaseSystem& fluid =
+        refCast<const twoPhaseSystem>(liquid.fluid());
     const transportModel& gas = fluid.otherPhase(liquid);
 
     volScalarField magUr(mag(this->U_ - gasTurbulence.U()));
diff --git a/src/TurbulenceModels/phaseCompressible/LES/SmagorinskyZhang/SmagorinskyZhang.C b/src/TurbulenceModels/phaseCompressible/LES/SmagorinskyZhang/SmagorinskyZhang.C
index 688a570030..47b0d4ff75 100644
--- a/src/TurbulenceModels/phaseCompressible/LES/SmagorinskyZhang/SmagorinskyZhang.C
+++ b/src/TurbulenceModels/phaseCompressible/LES/SmagorinskyZhang/SmagorinskyZhang.C
@@ -109,7 +109,8 @@ SmagorinskyZhang<BasicTurbulenceModel>::gasTurbulence() const
         const volVectorField& U = this->U_;
 
         const transportModel& liquid = this->transport();
-        const twoPhaseSystem& fluid = liquid.fluid();
+        const twoPhaseSystem& fluid =
+            refCast<const twoPhaseSystem>(liquid.fluid());
         const transportModel& gas = fluid.otherPhase(liquid);
 
         gasTurbulencePtr_ =
diff --git a/src/TurbulenceModels/phaseCompressible/LES/continuousGasKEqn/continuousGasKEqn.C b/src/TurbulenceModels/phaseCompressible/LES/continuousGasKEqn/continuousGasKEqn.C
index 96c1ad8808..c4d2efe6da 100644
--- a/src/TurbulenceModels/phaseCompressible/LES/continuousGasKEqn/continuousGasKEqn.C
+++ b/src/TurbulenceModels/phaseCompressible/LES/continuousGasKEqn/continuousGasKEqn.C
@@ -108,7 +108,8 @@ continuousGasKEqn<BasicTurbulenceModel>::liquidTurbulence() const
         const volVectorField& U = this->U_;
 
         const transportModel& gas = this->transport();
-        const twoPhaseSystem& fluid = gas.fluid();
+        const twoPhaseSystem& fluid =
+            refCast<const twoPhaseSystem>(gas.fluid());
         const transportModel& liquid = fluid.otherPhase(gas);
 
         liquidTurbulencePtr_ =
diff --git a/src/TurbulenceModels/phaseCompressible/RAS/LaheyKEpsilon/LaheyKEpsilon.C b/src/TurbulenceModels/phaseCompressible/RAS/LaheyKEpsilon/LaheyKEpsilon.C
index e9e02edf46..7c3b6a8aa9 100644
--- a/src/TurbulenceModels/phaseCompressible/RAS/LaheyKEpsilon/LaheyKEpsilon.C
+++ b/src/TurbulenceModels/phaseCompressible/RAS/LaheyKEpsilon/LaheyKEpsilon.C
@@ -145,7 +145,8 @@ LaheyKEpsilon<BasicTurbulenceModel>::gasTurbulence() const
         const volVectorField& U = this->U_;
 
         const transportModel& liquid = this->transport();
-        const twoPhaseSystem& fluid = liquid.fluid();
+        const twoPhaseSystem& fluid =
+            refCast<const twoPhaseSystem>(liquid.fluid());
         const transportModel& gas = fluid.otherPhase(liquid);
 
         gasTurbulencePtr_ =
@@ -186,7 +187,7 @@ tmp<volScalarField> LaheyKEpsilon<BasicTurbulenceModel>::bubbleG() const
         this->gasTurbulence();
 
     const transportModel& liquid = this->transport();
-    const twoPhaseSystem& fluid = liquid.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(liquid.fluid());
     const transportModel& gas = fluid.otherPhase(liquid);
 
     volScalarField magUr(mag(this->U_ - gasTurbulence.U()));
diff --git a/src/TurbulenceModels/phaseCompressible/RAS/continuousGasKEpsilon/continuousGasKEpsilon.C b/src/TurbulenceModels/phaseCompressible/RAS/continuousGasKEpsilon/continuousGasKEpsilon.C
index 0ae2dcff36..8d5f216dd2 100644
--- a/src/TurbulenceModels/phaseCompressible/RAS/continuousGasKEpsilon/continuousGasKEpsilon.C
+++ b/src/TurbulenceModels/phaseCompressible/RAS/continuousGasKEpsilon/continuousGasKEpsilon.C
@@ -120,7 +120,7 @@ void continuousGasKEpsilon<BasicTurbulenceModel>::correctNut()
 
     const turbulenceModel& liquidTurbulence = this->liquidTurbulence();
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
     const transportModel& liquid = fluid.otherPhase(gas);
 
     volScalarField thetal(liquidTurbulence.k()/liquidTurbulence.epsilon());
@@ -149,7 +149,8 @@ continuousGasKEpsilon<BasicTurbulenceModel>::liquidTurbulence() const
         const volVectorField& U = this->U_;
 
         const transportModel& gas = this->transport();
-        const twoPhaseSystem& fluid = gas.fluid();
+        const twoPhaseSystem& fluid =
+            refCast<const twoPhaseSystem>(gas.fluid());
         const transportModel& liquid = fluid.otherPhase(gas);
 
         liquidTurbulencePtr_ =
@@ -202,7 +203,7 @@ tmp<Foam::volScalarField>
 continuousGasKEpsilon<BasicTurbulenceModel>::rhoEff() const
 {
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
     const transportModel& liquid = fluid.otherPhase(gas);
 
     return tmp<volScalarField>
diff --git a/src/TurbulenceModels/phaseCompressible/RAS/mixtureKEpsilon/mixtureKEpsilon.C b/src/TurbulenceModels/phaseCompressible/RAS/mixtureKEpsilon/mixtureKEpsilon.C
index 453ca45dd2..f0b8a4f537 100644
--- a/src/TurbulenceModels/phaseCompressible/RAS/mixtureKEpsilon/mixtureKEpsilon.C
+++ b/src/TurbulenceModels/phaseCompressible/RAS/mixtureKEpsilon/mixtureKEpsilon.C
@@ -347,7 +347,8 @@ mixtureKEpsilon<BasicTurbulenceModel>::liquidTurbulence() const
         const volVectorField& U = this->U_;
 
         const transportModel& gas = this->transport();
-        const twoPhaseSystem& fluid = gas.fluid();
+        const twoPhaseSystem& fluid =
+            refCast<const twoPhaseSystem>(gas.fluid());
         const transportModel& liquid = fluid.otherPhase(gas);
 
         liquidTurbulencePtr_ =
@@ -375,7 +376,7 @@ tmp<volScalarField> mixtureKEpsilon<BasicTurbulenceModel>::Ct2() const
         this->liquidTurbulence();
 
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
     const transportModel& liquid = fluid.otherPhase(gas);
 
     const volScalarField& alphag = this->alpha_;
@@ -399,7 +400,7 @@ template<class BasicTurbulenceModel>
 tmp<volScalarField> mixtureKEpsilon<BasicTurbulenceModel>::rholEff() const
 {
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
     return fluid.otherPhase(gas).rho();
 }
 
@@ -408,7 +409,7 @@ template<class BasicTurbulenceModel>
 tmp<volScalarField> mixtureKEpsilon<BasicTurbulenceModel>::rhogEff() const
 {
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
     return
         gas.rho()
       + fluid.virtualMass(gas).Cvm()*fluid.otherPhase(gas).rho();
@@ -484,7 +485,7 @@ tmp<volScalarField> mixtureKEpsilon<BasicTurbulenceModel>::bubbleG() const
         this->liquidTurbulence();
 
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
     const transportModel& liquid = fluid.otherPhase(gas);
 
     volScalarField magUr(mag(liquidTurbulence.U() - this->U()));
@@ -531,7 +532,7 @@ template<class BasicTurbulenceModel>
 void mixtureKEpsilon<BasicTurbulenceModel>::correct()
 {
     const transportModel& gas = this->transport();
-    const twoPhaseSystem& fluid = gas.fluid();
+    const twoPhaseSystem& fluid = refCast<const twoPhaseSystem>(gas.fluid());
 
     // Only solve the mixture turbulence for the gas-phase
     if (&gas != &fluid.phase1())