diff --git a/src/parameterizations/vertical/MOM_diabatic_aux.F90 b/src/parameterizations/vertical/MOM_diabatic_aux.F90
index 6fdfdd5936..dcdbf82d39 100644
--- a/src/parameterizations/vertical/MOM_diabatic_aux.F90
+++ b/src/parameterizations/vertical/MOM_diabatic_aux.F90
@@ -1551,7 +1551,7 @@ subroutine applyBoundaryFluxesInOut(CS, G, GV, US, dt, fluxes, optics, nsw, h, t
             endif
             Ithickness  = 1.0/h2d(i,k) ! Inverse of new thickness
             T2d(i,k)    = (hOld*T2d(i,k) + dTemp)*Ithickness
-            tv%S(i,j,k) = (hOld*tv%S(i,j,k) + dSalt + plume_flux)*Ithickness
+            tv%S(i,j,k) = (hOld*tv%S(i,j,k) + (dSalt + plume_flux))*Ithickness
           elseif (h2d(i,k) < 0.0) then ! h2d==0 is a special limit that needs no extra handling
             call forcing_SinglePointPrint(fluxes,G,i,j,'applyBoundaryFluxesInOut (h<0)')
             write(0,*) 'applyBoundaryFluxesInOut(): lon,lat=',G%geoLonT(i,j),G%geoLatT(i,j)