diff --git a/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmAlphatkWallFunction/atmAlphatkWallFunctionFvPatchScalarField.C b/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmAlphatkWallFunction/atmAlphatkWallFunctionFvPatchScalarField.C
index 2633d9ada4..570544a68e 100644
--- a/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmAlphatkWallFunction/atmAlphatkWallFunctionFvPatchScalarField.C
+++ b/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmAlphatkWallFunction/atmAlphatkWallFunctionFvPatchScalarField.C
@@ -249,7 +249,7 @@ void atmAlphatkWallFunctionFvPatchScalarField::updateCoeffs()
 
     // lower bound values to avoid unrealistic
     // negative temperatures on the ground
-    alphatw = max(alphatw, 0.01);
+    alphatw = max(alphatw, scalar(0.01));
 
     fixedValueFvPatchField<scalar>::updateCoeffs();
 }
diff --git a/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutUWallFunction/atmNutUWallFunctionFvPatchScalarField.C b/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutUWallFunction/atmNutUWallFunctionFvPatchScalarField.C
index 9715f8db8a..2bbfcfb541 100644
--- a/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutUWallFunction/atmNutUWallFunctionFvPatchScalarField.C
+++ b/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutUWallFunction/atmNutUWallFunctionFvPatchScalarField.C
@@ -90,7 +90,7 @@ tmp<scalarField> atmNutUWallFunctionFvPatchScalarField::calcNut() const
 
     if (boundNut_)
     {
-        nutw = max(nutw, 0.0);
+        nutw = max(nutw, scalar(0.0));
     }
 
     return tnutw;
diff --git a/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutkWallFunction/atmNutkWallFunctionFvPatchScalarField.C b/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutkWallFunction/atmNutkWallFunctionFvPatchScalarField.C
index 45c8f4614e..79d9c57a22 100644
--- a/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutkWallFunction/atmNutkWallFunctionFvPatchScalarField.C
+++ b/src/atmosphericModels/derivedFvPatchFields/wallFunctions/atmNutkWallFunction/atmNutkWallFunctionFvPatchScalarField.C
@@ -98,7 +98,7 @@ tmp<scalarField> atmNutkWallFunctionFvPatchScalarField::calcNut() const
 
     if (boundNut_)
     {
-        nutw = max(nutw, 0.0);
+        nutw = max(nutw, scalar(0.0));
     }
 
     return tnutw;