--- CairoSurface.xs.orig	2024-10-04 13:12:20.636290906 +0000
+++ CairoSurface.xs	2024-10-04 13:12:53.600240731 +0000
@@ -389,11 +389,11 @@ cairo_status_t
 cairo_surface_set_mime_data (cairo_surface_t *surface, const char *mime_type, SV *data);
     PREINIT:
 	const unsigned char *mime_data;
-	unsigned long length;
+	STRLEN length;
     CODE:
 	SvREFCNT_inc (data);
 	mime_data = (const unsigned char *) SvPV(data, length);
-	RETVAL = cairo_surface_set_mime_data (surface, mime_type, mime_data, length, data_destroy, data);
+	RETVAL = cairo_surface_set_mime_data (surface, mime_type, mime_data, (unsigned long)length, data_destroy, data);
     OUTPUT:
 	RETVAL