diff --git a/obl_inmom.f90 b/obl_inmom.f90
index d51587a3acb481bee7f06bf631c830bc66761a09..f70f53c548129e95c2b51f70975c6fd4eb54ccfb 100644
--- a/obl_inmom.f90
+++ b/obl_inmom.f90
@@ -118,6 +118,8 @@ module obl_inmom
       end do
     ! obl_pph mixing mode (lake constants)
     else if (kh_km_mode == 2) then
+      pphParams%Kh_unstable = 0.05
+      pphParams%Km_unstable = 0.05
       do j = 1, ny
         do i = 1, nx
           if (lu(i, j) > lu_min) then
@@ -136,6 +138,8 @@ module obl_inmom
       pphParams%n = 2.0
       pphParams%Km_b = 5e-6
       pphParams%Kh_b = 0.00001
+      pphParams%Kh_unstable = 0.05
+      pphParams%Km_unstable = 0.05
       do j = 1, ny
         do i = 1, nx
           if (lu(i, j) > lu_min) then
@@ -148,6 +152,8 @@ module obl_inmom
       km = km * 10000.0
     ! obl_pph_dyn mixing mode
     else if (kh_km_mode == 4) then
+      pphDynParams%Kh_unstable = 0.05
+      pphDynParams%Km_unstable = 0.05
       do j = 1, ny
         do i = 1, nx
           if (lu(i, j) > lu_min) then