diff --git a/cellpose/export.py b/cellpose/export.py
index 78a92ece..ffc6bc46 100644
--- a/cellpose/export.py
+++ b/cellpose/export.py
@@ -54,7 +54,6 @@
 from cellpose.resnet_torch import CPnetBioImageIO
 
 from bioimageio.spec.model.v0_5 import (
-    ARBITRARY_SIZE,
     ArchitectureFromFileDescr,
     Author,
     AxisId,