Fix label syntax.
diff --git a/Doc/library/urllib.parse.rst b/Doc/library/urllib.parse.rst
index 037d4c4..6a143c5 100644
--- a/Doc/library/urllib.parse.rst
+++ b/Doc/library/urllib.parse.rst
@@ -281,7 +281,7 @@
    .. versionchanged:: 3.2
       Result is a structured object rather than a simple 2-tuple.
 
-:: _parsing-ascii-encoded-bytes:
+.. _parsing-ascii-encoded-bytes:
 
 Parsing ASCII Encoded Bytes
 ---------------------------