# OPF-043: spine item without fallback, how to fix it

Source: https://epubcc.com/epubcheck/opf-043/ (updated 2026-11-04)

EPUBCheck OPF-043 is an error message: “Spine item with non-standard media-type "…" has no fallback.” The spine lists a file that is not an EPUB content document and gives no fallback to one. Reading apps must be able to show every spine item, so a foreign file needs a fallback chain ending in XHTML or SVG.

- Official message (EPUBCheck 5.4.0): Spine item with non-standard media-type "%1$s" has no fallback.
- Default severity: Error

## Typical causes

- An image, PDF or other non-XHTML file placed directly in the spine.
- A spine item whose fallback attribute was removed.
- A media type typo that makes an XHTML file look like a foreign one.

## How to fix it

1. Read the media type EPUBCheck names; if it is a typo for application/xhtml+xml, fix the manifest.
2. Otherwise wrap the resource in an XHTML document and put that in the spine.
3. Or give the item a fallback attribute pointing to a content document with the same content.

## When it's not this

If a fallback exists but none of its items is a content document, that is OPF-044.

## Sources

- EPUB 3.3, §3.5.1 Manifest fallbacks: https://www.w3.org/TR/epub-33/#sec-manifest-fallbacks (read 2026-11-04)
- EPUB 3.3, §5.7.2 The itemref element: https://www.w3.org/TR/epub-33/#sec-itemref-elem (read 2026-11-04)

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EpubCC.