diff --git a/internal/handlers/media.go b/internal/handlers/media.go
index 6a1631d7..ec9365ce 100644
--- a/internal/handlers/media.go
+++ b/internal/handlers/media.go
@@ -1610,6 +1610,14 @@ func (mh *MediaHandler) UpdateMediaItem(c *echo.Context) error {
 		Summary:            pgtype.Text{String: req.Summary, Valid: req.Summary != ""},
 	}
 
+	// audio_metadata is scan-owned (track manifest, chapters, duration)
+	// and has no editor field: the full-row update writes it
+	// unconditionally, so an unguarded save NULLed every audiobook's
+	// payload — books dropped back to "1 second long" on a plain
+	// metadata edit (2026-10-21 incident class). Write-after-success:
+	// carry the existing bytes; only the audio chain replaces them.
+	params.AudioMetadata = existing.AudioMetadata
+
 	// Fields the user actually changed become overrides so future scans keep
 	// the custom values. An explicit cover upload/removal always overrides.
 	overrides := utils.DetectMetadataOverrides(params, existing)