@@ -468,3 +468,27 @@ function webp_uploads_get_mime_type_image( int $attachment_id, string $src, stri
 
 	return null;
 }
+
+/**
+ * Retrieves the MIME type of a file, checking the file directly if possible,
+ * and falling back to the attachment's MIME type if needed.
+ *
+ * The function attempts to determine the MIME type directly from the file.
+ * If that information is unavailable, it uses the MIME type from the attachment metadata.
+ * If neither is available, it defaults to an empty string.
+ *
+ * @since n.e.x.t
+ *
+ * @param string $file          The path to the file.
+ * @param int    $attachment_id The attachment ID.
+ * @return string The MIME type of the file, or an empty string if not found.
+ */
+function webp_uploads_get_file_mime_type( string $file, int $attachment_id ): string {
+	/*
+	 * We need to get the MIME type ideally from the file, as WordPress Core may have already altered it.
+	 * The post MIME type is typically not updated during that process.
+	 */
+	$filetype  = wp_check_filetype( $file );
+	$mime_type = $filetype['type'] ?? get_post_mime_type( $attachment_id );
+	return is_string( $mime_type ) ? $mime_type : '';
+}
@@ -58,13 +58,8 @@ function webp_uploads_create_sources_property( array $metadata, int $attachment_
 		return $metadata;
 	}
 
-	/*
-	 * We need to get the MIME type ideally from the file, as WordPress Core may have already altered it.
-	 * The post MIME type is typically not updated during that process.
-	 */
-	$filetype  = wp_check_filetype( $file );
-	$mime_type = $filetype['type'] ?? get_post_mime_type( $attachment_id );
-	if ( ! is_string( $mime_type ) ) {
+	$mime_type = webp_uploads_get_file_mime_type( $file, $attachment_id );
+	if ( '' === $mime_type ) {
 		return $metadata;
 	}
 
 
@@ -22,9 +22,21 @@ function webp_uploads_wrap_image_in_picture( string $image, string $context, int
 	if ( 'the_content' !== $context ) {
 		return $image;
 	}
-	$image_meta              = wp_get_attachment_metadata( $attachment_id );
-	$original_file_mime_type = get_post_mime_type( $attachment_id );
-	if ( false === $original_file_mime_type || ! isset( $image_meta['sizes'] ) ) {
+
+	$file = get_attached_file( $attachment_id, true );
+	// File does not exist.
+	if ( false === $file || ! file_exists( $file ) ) {
+		return $image;
+	}
+
+	$original_file_mime_type = webp_uploads_get_file_mime_type( $file, $attachment_id );
+	if ( '' === $original_file_mime_type ) {
+		return $image;
+	}
+
+	$image_meta = wp_get_attachment_metadata( $attachment_id );
+
+	if ( ! isset( $image_meta['sizes'] ) ) {
 		return $image;
 	}
Original file line number	Diff line number	Diff line change
`@@ -58,13 +58,8 @@ function webp_uploads_create_sources_property( array $metadata, int $attachment_`
`58`	`58`	`return $metadata;`
`59`	`59`	`}`
`60`	`60`
`61`		`- /*`
`62`		`- * We need to get the MIME type ideally from the file, as WordPress Core may have already altered it.`
`63`		`- * The post MIME type is typically not updated during that process.`
`64`		`- */`
`65`		`- $filetype = wp_check_filetype( $file );`
`66`		`- $mime_type = $filetype['type'] ?? get_post_mime_type( $attachment_id );`
`67`		`- if ( ! is_string( $mime_type ) ) {`
	`61`	`+ $mime_type = webp_uploads_get_file_mime_type( $file, $attachment_id );`
	`62`	`+ if ( '' === $mime_type ) {`
`68`	`63`	`return $metadata;`
`69`	`64`	`}`
`70`	`65`