diff --git a/Lib/urllib/parse.py b/Lib/urllib/parse.py
index 0b96b5b41d3..ffb0ff72dfe 100644
--- a/Lib/urllib/parse.py
+++ b/Lib/urllib/parse.py
@@ -221,6 +221,11 @@ def urlunparse(components):
     return urlunsplit((scheme, netloc, url, query, fragment))
 
 def urlunsplit(components):
+    """Combine the elements of a tuple as returned by urlsplit() into a
+    complete URL as a string. The data argument can be any five-item iterable.
+    This may result in a slightly different, but equivalent URL, if the URL that
+    was parsed originally had unnecessary delimiters (for example, a ? with an
+    empty query; the RFC states that these are equivalent)."""
     scheme, netloc, url, query, fragment = components
     if netloc or (scheme and scheme in uses_netloc and url[:2] != '//'):
         if url and url[:1] != '/': url = '/' + url