diff --git a/mercurial/hgweb/webutil.py b/mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py
+++ b/mercurial/hgweb/webutil.py
@@ -423,7 +423,8 @@ def commonentry(repo, ctx):
         'phase': ctx.phasestr(),
         'obsolete': ctx.obsolete(),
         'succsandmarkers': succsandmarkers,
-        'instabilities': [{"instability": i} for i in ctx.instabilities()],
+        'instabilities': templateutil.hybridlist(ctx.instabilities(),
+                                                 name='instability'),
         'whyunstable': whyunstable,
         'branch': nodebranchnodefault(ctx),
         'inbranch': nodeinbranch(repo, ctx),