diff -r 8b2040ba4785 sys/src/cmd/upas/marshal/marshal.c
--- a/sys/src/cmd/upas/marshal/marshal.c	Fri Nov 22 17:29:35 2019 +1030
+++ b/sys/src/cmd/upas/marshal/marshal.c	Fri Nov 22 11:59:56 2019 +0100
@@ -902,7 +902,7 @@
 	}
 
 	/* pick a type depending on extension */
-	p = strchr(file, '.');
+	p = strrchr(file, '.');
 	if(p != nil)
 		p++;