diff --git a/src/gray_tables.f90 b/src/gray_tables.f90
index 60ff18a..60cefbd 100644
--- a/src/gray_tables.f90
+++ b/src/gray_tables.f90
@@ -178,7 +178,7 @@ contains
     ! Δρ_p for the uniform ρ_p grid
     drho_p = 1.0_wp_ / (n_grid - 1)
 
-    do i = 0, n_grid
+    do i = 0, n_grid-1
       rho_p = i * drho_p
       rho_t = equil%pol2tor(rho_p)
       call equil%flux_average(rho_p,       &