diff --git a/lib/asn1/test.asn1 b/lib/asn1/test.asn1
index 206e1c328..3b70a02cd 100644
--- a/lib/asn1/test.asn1
+++ b/lib/asn1/test.asn1
@@ -7,7 +7,7 @@ BEGIN
 IMPORTS heim_any FROM heim;
 
 TESTuint32 ::= INTEGER (0..4294967295)
-TESTuint64 ::= INTEGER(0..18446744073709551615)
+TESTuint64 ::= INTEGER(0..9223372036854775807)
 TESTint64 ::= INTEGER(-9223372036854775808..9223372036854775807)
 
 TESTLargeTag ::= SEQUENCE {