diff --git a/src/define_surface.f90 b/src/define_surface.f90
index 5a0228a469d5dffc51e704caa819bcc60490fdcc..4212712bcd5e69c0f43c47b16598f5cc68bfee11 100644
--- a/src/define_surface.f90
+++ b/src/define_surface.f90
@@ -168,7 +168,7 @@ else
                i=1,nnode)
    read (9) (nf,i=1,nface)
    ! read surface information
-   do is=1,nlsf                                    
+   do is=1,nlsf
       read (9) surface(is)%nsurface, &
                  activation_time,      &
                  surface(is)%nt