diff --git a/src/utils_cc/occupancy.irp.f b/src/utils_cc/occupancy.irp.f
index c6139bb3..27b0ee5e 100644
--- a/src/utils_cc/occupancy.irp.f
+++ b/src/utils_cc/occupancy.irp.f
@@ -204,8 +204,8 @@ function is_del(i)
   is_del = .False.
 
   ! Search
-  do j = 1, dim_list_core_orb
-    if (list_core(j) == i) then
+  do j = 1, dim_list_del_orb
+    if (list_del(j) == i) then
       is_del = .True.
       exit
     endif
diff --git a/src/utils_cc/org/occupancy.org b/src/utils_cc/org/occupancy.org
index 246bbd5b..4267fc88 100644
--- a/src/utils_cc/org/occupancy.org
+++ b/src/utils_cc/org/occupancy.org
@@ -209,8 +209,8 @@ function is_del(i)
   is_del = .False.
 
   ! Search
-  do j = 1, dim_list_core_orb
-    if (list_core(j) == i) then
+  do j = 1, dim_list_del_orb
+    if (list_del(j) == i) then
       is_del = .True.
       exit
     endif