diff --git a/make_bin_table.pro b/make_bin_table.pro
index 01f721a778084c3bba1da020c3b33c2daca2e1bc..c322ba1c332303d6366680357ed6d9344a203cd2 100644
--- a/make_bin_table.pro
+++ b/make_bin_table.pro
@@ -3,8 +3,9 @@ function make_bin_table, table
     gen_time = dblarr(n)
     for k = 0, n - 1 do gen_time[k] = date_conv(table.gen_time[k], 'JULIAN')
 
-    w = where(table.eng_val.contains('N/A'))
-    table.eng_val[w] = table.raw_val[w]
+    s = where(table.eng_val.contains('N/A'), count)
+    if count gt 0 then table.eng_val[s] = table.raw_val[s]
+
     par_names = table.par_name
     s = sort(par_names)
     par_names = par_names[s]