diff --git a/src/turbulenceModels/compressible/RAS/derivedFvPatchFields/wallFunctions/mutWallFunctions/mutUSpaldingWallFunction/mutUSpaldingWallFunctionFvPatchScalarField.C b/src/turbulenceModels/compressible/RAS/derivedFvPatchFields/wallFunctions/mutWallFunctions/mutUSpaldingWallFunction/mutUSpaldingWallFunctionFvPatchScalarField.C
index a541a35bcf..231c61939e 100644
--- a/src/turbulenceModels/compressible/RAS/derivedFvPatchFields/wallFunctions/mutWallFunctions/mutUSpaldingWallFunction/mutUSpaldingWallFunctionFvPatchScalarField.C
+++ b/src/turbulenceModels/compressible/RAS/derivedFvPatchFields/wallFunctions/mutWallFunctions/mutUSpaldingWallFunction/mutUSpaldingWallFunctionFvPatchScalarField.C
@@ -66,10 +66,9 @@ tmp<scalarField> mutUSpaldingWallFunctionFvPatchScalarField::calcUTau
     forAll(mutw, faceI)
     {
         scalar ut =
-            sqrt((mutw[faceI] + muw[faceI])*magGradU[faceI]/rhow[faceI])
-          + ROOTVSMALL;
+            sqrt((mutw[faceI] + muw[faceI])*magGradU[faceI]/rhow[faceI]);
 
-        if (ut > VSMALL)
+        if (ut > ROOTVSMALL)
         {
             int iter = 0;
             scalar err = GREAT;
@@ -93,7 +92,7 @@ tmp<scalarField> mutUSpaldingWallFunctionFvPatchScalarField::calcUTau
                 err = mag((ut - uTauNew)/ut);
                 ut = uTauNew;
 
-            } while (ut > VSMALL && err > 0.01 && ++iter < 10);
+            } while (ut > ROOTVSMALL && err > 0.01 && ++iter < 10);
 
             uTau[faceI] = max(0.0, ut);
         }
@@ -109,11 +108,15 @@ tmp<scalarField> mutUSpaldingWallFunctionFvPatchScalarField::calcMut() const
 
     const RASModel& rasModel = db().lookupObject<RASModel>("RASProperties");
     const fvPatchVectorField& Uw = rasModel.U().boundaryField()[patchI];
-    const scalarField magGradU = mag(Uw.snGrad()) + ROOTVSMALL;
+    const scalarField magGradU = mag(Uw.snGrad());
     const scalarField& rhow = rasModel.rho().boundaryField()[patchI];
     const scalarField& muw = rasModel.mu().boundaryField()[patchI];
 
-    return max(scalar(0), rhow*sqr(calcUTau(magGradU))/magGradU - muw);
+    return max
+    (
+        scalar(0),
+        rhow*sqr(calcUTau(magGradU))/(magGradU + ROOTVSMALL) - muw
+    );
 }
 
 
diff --git a/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUSpaldingWallFunction/nutUSpaldingWallFunctionFvPatchScalarField.C b/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUSpaldingWallFunction/nutUSpaldingWallFunctionFvPatchScalarField.C
index 950f8c88a8..0b11e08f2d 100644
--- a/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUSpaldingWallFunction/nutUSpaldingWallFunctionFvPatchScalarField.C
+++ b/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUSpaldingWallFunction/nutUSpaldingWallFunctionFvPatchScalarField.C
@@ -46,10 +46,14 @@ tmp<scalarField> nutUSpaldingWallFunctionFvPatchScalarField::calcNut() const
 
     const RASModel& rasModel = db().lookupObject<RASModel>("RASProperties");
     const fvPatchVectorField& Uw = rasModel.U().boundaryField()[patchI];
-    const scalarField magGradU = mag(Uw.snGrad()) + ROOTVSMALL;
+    const scalarField magGradU = mag(Uw.snGrad());
     const scalarField& nuw = rasModel.nu().boundaryField()[patchI];
 
-    return max(scalar(0), sqr(calcUTau(magGradU))/magGradU - nuw);
+    return max
+    (
+        scalar(0),
+        sqr(calcUTau(magGradU))/(magGradU + ROOTVSMALL) - nuw
+    );
 }
 
 
@@ -73,10 +77,9 @@ tmp<scalarField> nutUSpaldingWallFunctionFvPatchScalarField::calcUTau
 
     forAll(uTau, facei)
     {
-        scalar ut =
-            sqrt((nutw[facei] + nuw[facei])*magGradU[facei]) + ROOTVSMALL;
+        scalar ut = sqrt((nutw[facei] + nuw[facei])*magGradU[facei]);
 
-        if (ut > VSMALL)
+        if (ut > ROOTVSMALL)
         {
             int iter = 0;
             scalar err = GREAT;
@@ -100,7 +103,7 @@ tmp<scalarField> nutUSpaldingWallFunctionFvPatchScalarField::calcUTau
                 err = mag((ut - uTauNew)/ut);
                 ut = uTauNew;
 
-            } while (ut > VSMALL && err > 0.01 && ++iter < 10);
+            } while (ut > ROOTVSMALL && err > 0.01 && ++iter < 10);
 
             uTau[facei] = max(0.0, ut);
         }
diff --git a/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUTabulatedWallFunction/nutUTabulatedWallFunctionFvPatchScalarField.C b/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUTabulatedWallFunction/nutUTabulatedWallFunctionFvPatchScalarField.C
index d6e1127b4d..79e9ab8383 100644
--- a/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUTabulatedWallFunction/nutUTabulatedWallFunctionFvPatchScalarField.C
+++ b/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/wallFunctions/nutWallFunctions/nutUTabulatedWallFunction/nutUTabulatedWallFunctionFvPatchScalarField.C
@@ -48,14 +48,16 @@ tmp<scalarField> nutUTabulatedWallFunctionFvPatchScalarField::calcNut() const
     const scalarField& y = rasModel.y()[patchI];
     const fvPatchVectorField& Uw = rasModel.U().boundaryField()[patchI];
     const scalarField magUp = mag(Uw.patchInternalField() - Uw);
-    const scalarField magGradU = mag(Uw.snGrad()) + ROOTVSMALL;
+    const scalarField magGradU = mag(Uw.snGrad());
     const scalarField& nuw = rasModel.nu().boundaryField()[patchI];
 
     return
         max
         (
             scalar(0),
-            sqr(magUp/(calcUPlus(magUp*y/nuw) + ROOTVSMALL))/magGradU - nuw
+            sqr(magUp/(calcUPlus(magUp*y/nuw) + ROOTVSMALL))
+           /(magGradU + ROOTVSMALL)
+          - nuw
         );
 }
 
@@ -190,7 +192,6 @@ tmp<scalarField> nutUTabulatedWallFunctionFvPatchScalarField::yPlus() const
 void nutUTabulatedWallFunctionFvPatchScalarField::write(Ostream& os) const
 {
     fvPatchField<scalar>::write(os);
-//    writeLocalEntries(os); // not applicable to this nut BC
     os.writeKeyword("uPlusTable") << uPlusTableName_
         << token::END_STATEMENT << nl;
     writeEntry("value", os);