diff --git a/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.C b/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.C
index d01a0079..eeb30de7 100644
--- a/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.C
+++ b/src/turbulenceModels/incompressible/RAS/derivedFvPatchFields/atmBoundaryLayer/atmBoundaryLayer.C
@@ -73,7 +73,7 @@ atmBoundaryLayer::atmBoundaryLayer(const vectorField& p, const dictionary& dict)
     flowDir_ /= mag(flowDir_);
     zDir_ /= mag(zDir_);
 
-    Ustar_ = kappa_*Uref_/(log((Zref_ + z0_)/max(z0_, 0.001)));
+    Ustar_ = kappa_*Uref_/(log((Zref_ + z0_)/max(z0_, scalar(0.001))));
 }
 
 
@@ -136,7 +136,7 @@ tmp<vectorField> atmBoundaryLayer::U(const vectorField& p) const
     scalarField Un
     (
         (Ustar_/kappa_)
-       *log(((zDir_ & p) - zGround_ + z0_)/max(z0_, 0.001))
+        *log(((zDir_ & p) - zGround_ + z0_)/max(z0_, scalar(0.001)))
     );
 
     return flowDir_*Un;