diff --git a/src/OCE/DIA/diahth.F90 b/src/OCE/DIA/diahth.F90
index dc71bfa7d5f5cc89d5c39c6a289f962f8200362f..f66bf3c97c61eb3fd016c626cb4a66648b3a8552 100644
--- a/src/OCE/DIA/diahth.F90
+++ b/src/OCE/DIA/diahth.F90
@@ -306,7 +306,7 @@ CONTAINS
          IF( iid /= 1 ) THEN 
              zztmp =     gdept(ji,jj,iid  ,Kmm)   &                     ! linear interpolation
                &  + (    gdept(ji,jj,iid+1,Kmm) - gdept(ji,jj,iid,Kmm)                       )   &
-               &  * ( 20.*tmask(ji,jj,iid+1) - ts(ji,jj,iid,jp_tem,Kmm)                       )   &
+               &  * ( ptem*tmask(ji,jj,iid+1)    - ts(ji,jj,iid,jp_tem,Kmm)                  )   &
                &  / ( ts(ji,jj,iid+1,jp_tem,Kmm) - ts(ji,jj,iid,jp_tem,Kmm) + (1.-tmask(ji,jj,1)) )
             pdept(ji,jj) = MIN( zztmp , zzdep) * tmask(ji,jj,1)       ! bound by the ocean depth
          ELSE