diff --git a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C
index 54131aa829..6800360b40 100644
--- a/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C
+++ b/src/lagrangian/intermediate/submodels/Kinematic/CollisionModel/PairCollision/PairCollision.C
@@ -246,7 +246,7 @@ void Foam::PairCollision<CloudType>::wallInteraction()
 
                     vector pW = nearPt - pos;
 
-                    scalar normalAlignment = normal & pW/(mag(pW) + ROOTSMALL);
+                    scalar normalAlignment = normal & pW/(mag(pW) + SMALL);
 
                     // Find the patchIndex and wallData for WallSiteData object
                     label patchI = patchID[realFaceI - mesh.nInternalFaces()];