diff --git a/masque/utils/pack2d.py b/masque/utils/pack2d.py
index ce6b006..a99b01e 100644
--- a/masque/utils/pack2d.py
+++ b/masque/utils/pack2d.py
@@ -236,7 +236,9 @@ def pack_patterns(
     locations, reject_inds = packer(sizes, containers, presort=presort, allow_rejects=allow_rejects)
 
     pat = Pattern()
-    for pp, oo, loc in zip(patterns, offsets, locations, strict=True):
+    for ii, (pp, oo, loc) in enumerate(zip(patterns, offsets, locations, strict=True)):
+        if ii in reject_inds:
+            continue
         pat.ref(pp, offset=oo + loc)
 
     rejects = [patterns[ii] for ii in reject_inds]