diff --git a/src/lagrangian/dieselSpray/spraySubModels/collisionModel/trajectoryModel/trajectoryCM.H b/src/lagrangian/dieselSpray/spraySubModels/collisionModel/trajectoryModel/trajectoryCM.H
index fd01d4390d9deada238edd3995992afd599e4640..a7cca2b7e36c99ceff987257c4c3eb1c4e8faccf 100644
--- a/src/lagrangian/dieselSpray/spraySubModels/collisionModel/trajectoryModel/trajectoryCM.H
+++ b/src/lagrangian/dieselSpray/spraySubModels/collisionModel/trajectoryModel/trajectoryCM.H
@@ -8,7 +8,7 @@ scalar magVRel = mag(vRel);
 vector p = p2().position() - p1().position();
 scalar dist = mag(p);
 
-scalar vAlign = vRel & (p/dist);
+scalar vAlign = vRel & (p/(dist+SMALL));
 
 if (vAlign > 0)
 {