diff --git a/src/crater/crater_subpixel_diffusion.f90 b/src/crater/crater_subpixel_diffusion.f90
index a47c3851..2a97e6f3 100644
--- a/src/crater/crater_subpixel_diffusion.f90
+++ b/src/crater/crater_subpixel_diffusion.f90
@@ -124,7 +124,7 @@ subroutine crater_subpixel_diffusion(user,surf,prod,nflux,domain,finterval,kdiff
          end if
 
          dN(i) = nflux(3,i) * user%interval * finterval
-         Area = min(PI * (user%soften_size * radius)**2 , PI * user%trad**2)
+         Area = min(PI * (user%soften_size * radius)**2 , 4 * PI * user%trad**2)
          Area = max(Area - (user%pix * user%gridsize)**2,0.0_DP)
          if (Area == 0.0_DP) cycle
          lambda = dN(i) * Area