diff --git a/cdm/zarr/src/test/java/thredds/inventory/zarr/TestMFileZip.java b/cdm/zarr/src/test/java/thredds/inventory/zarr/TestMFileZip.java
index 4690705b2d..3fd90fc74c 100644
--- a/cdm/zarr/src/test/java/thredds/inventory/zarr/TestMFileZip.java
+++ b/cdm/zarr/src/test/java/thredds/inventory/zarr/TestMFileZip.java
@@ -52,7 +52,7 @@ public void shouldWriteZipToStream() throws IOException {
 
         final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
         mFile.writeToStream(outputStream);
-        assertThat(outputStream.size()).isEqualTo(expectedSize * expectedNumberOfFiles);
+        assertThat(outputStream.size()).isEqualTo(mFile.getLength());
       }
     }
   }