diff --git a/src/functionObjects/field/wallShearStress/wallShearStress.C b/src/functionObjects/field/wallShearStress/wallShearStress.C
index c762190fc8..a31714a406 100644
--- a/src/functionObjects/field/wallShearStress/wallShearStress.C
+++ b/src/functionObjects/field/wallShearStress/wallShearStress.C
@@ -64,6 +64,8 @@ void Foam::functionObjects::wallShearStress::calcShearStress
     volVectorField& shearStress
 )
 {
+    shearStress.dimensions().reset(Reff.dimensions());
+
     forAllConstIter(labelHashSet, patchSet_, iter)
     {
         label patchi = iter.key();