diff --git a/index.bs b/index.bs
index 16dd374e8..5de0cb12e 100644
--- a/index.bs
+++ b/index.bs
@@ -3179,7 +3179,7 @@ The attestation certificate MUST have the following fields/extensions:
 - Version MUST be set to 3 (which is indicated by an ASN.1 INTEGER with value 2).
 - Subject field MUST be set to:
     : Subject-C
-    :: ISO 3166 code specifying the country where the Authenticator vendor is incorporated (UTF8String)
+    :: ISO 3166 code specifying the country where the Authenticator vendor is incorporated (PrintableString)
     : Subject-O
     :: Legal name of the Authenticator vendor (UTF8String)
     : Subject-OU