diff --git a/src/list.c b/src/list.c
index 4531e58..2b44eba 100644
--- a/src/list.c
+++ b/src/list.c
@@ -2188,10 +2188,13 @@
 		int		stride = l->lv_u.nonmat.lv_stride;
 
 		// List from range(): loop over the numbers
-		l->lv_first = NULL;
-		l->lv_u.mat.lv_last = NULL;
-		l->lv_len = 0;
-		l->lv_u.mat.lv_idx_item = NULL;
+		if (filtermap != FILTERMAP_MAPNEW)
+		{
+		    l->lv_first = NULL;
+		    l->lv_u.mat.lv_last = NULL;
+		    l->lv_len = 0;
+		    l->lv_u.mat.lv_idx_item = NULL;
+		}
 
 		for (idx = 0; idx < len; ++idx)
 		{