diff --git a/stdlib/uri/0/common.rbs b/stdlib/uri/0/common.rbs
index ee3241802..97505f1e3 100644
--- a/stdlib/uri/0/common.rbs
+++ b/stdlib/uri/0/common.rbs
@@ -560,6 +560,11 @@ URI::REL_URI: Regexp
 
 URI::REL_URI_REF: Regexp
 
+# <!-- rdoc-file=lib/uri/common.rb -->
+# The default parser instance for RFC 2396.
+#
+URI::RFC2396_PARSER: URI::RFC2396_Parser
+
 # <!-- rdoc-file=lib/uri/common.rb -->
 # The default parser instance for RFC 3986.
 #