diff --git a/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C b/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C
index 28a6acdbaa2b959beaa76fe1f05c0b75170e8048..48277b261d94650f8401b4255335dc8095657363 100644
--- a/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C
+++ b/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C
@@ -199,7 +199,7 @@ tmp<volScalarField> kinematicSingleLayer::pp()
 
 void kinematicSingleLayer::correctAlpha()
 {
-    alpha_ == pos(delta_ - dimensionedScalar("SMALL", dimless, SMALL));
+    alpha_ == pos(delta_ - dimensionedScalar("SMALL", dimLength, SMALL));
 }