diff --git a/source/model/trib.f90 b/source/model/trib.f90
index 051633965c44d11de05c962e268fc62997b80b31..0e76961acaf99e9768192594cc995cabc813c05f 100644
--- a/source/model/trib.f90
+++ b/source/model/trib.f90
@@ -278,6 +278,7 @@ SUBROUTINE TRIBTEMP(time,dt,h1,dhwtrib,z_full,area_int,area_half,gsp,gas,wst,spi
      wst%wArea(i-1) = wst%wArea(i) - gsp%ddz05(i-1)*h1*(inflow - outflow) !Solution of horizontally averaged continuity
      !print*, i, wst%wArea(i-1), wst%wArea(i), gsp%ddz05(i),h1,inflow , outflow !Solution of horizontally averaged continuity
      outflow = outflow/area_int(i)
+     outflow = max(outflow,0.) !Ensuring positivity of outflow discharge, used for advection only
      !print*, 'outflow', outflow, U_tribin_(1,i),T_tribin_(1,i),width_tribin_(1,i), area_int(i), invdt
 
      meanTin = 0.