diff --git a/src/main/java/com/glencoesoftware/omero/zarr/ZarrPixelsService.java b/src/main/java/com/glencoesoftware/omero/zarr/ZarrPixelsService.java
index 0792904..4a3ef1a 100644
--- a/src/main/java/com/glencoesoftware/omero/zarr/ZarrPixelsService.java
+++ b/src/main/java/com/glencoesoftware/omero/zarr/ZarrPixelsService.java
@@ -325,7 +325,7 @@ protected ZarrPixelBuffer createOmeNgffPixelBuffer(Pixels pixels) {
             String uri = getUri(image);
             if (uri == null) {
                 // Quick exit if we think we're OME-NGFF but there is no URI
-                if ("OMEXML".equals(image.getFormat().getValue())) {
+                if (image.getFormat() != null && "OMEXML".equals(image.getFormat().getValue())) {
                     throw new LockTimeout("Import in progress.", 15*1000, 0);
                 }
                 log.debug("No OME-NGFF root");