Index: mount_msdosfs.c
===================================================================
--- mount_msdosfs.c	(revision 313274)
+++ mount_msdosfs.c	(working copy)
@@ -43,6 +43,7 @@
 #include <sys/module.h>
 
 #include <ctype.h>
+#include <errno.h>
 #include <err.h>
 #include <grp.h>
 #include <locale.h>
@@ -306,17 +307,17 @@
 
 	build_iovec_argf(iov, iovlen, "cs_win", ENCODING_UNICODE);
 	error = kiconv_add_xlat16_cspairs(ENCODING_UNICODE, cs_local);
-	if (error)
+	if (error && errno != EEXIST)
 		return (-1);
 	if (cs_dos != NULL) {
 		error = kiconv_add_xlat16_cspairs(cs_dos, cs_local);
-		if (error)
+		if (error && errno != EEXIST)
 			return (-1);
 	} else {
 		build_iovec_argf(iov, iovlen, "cs_dos", cs_local);
 		error = kiconv_add_xlat16_cspair(cs_local, cs_local,
 				KICONV_FROM_UPPER | KICONV_LOWER);
-		if (error)
+		if (error && errno != EEXIST)
 			return (-1);
 	}