diff --git a/mercurial/minirst.py b/mercurial/minirst.py
--- a/mercurial/minirst.py
+++ b/mercurial/minirst.py
@@ -697,7 +697,7 @@ def format(text, width=80, indent=0, kee
         if collapse:
             synthetic.reverse()
             for s in synthetic:
-                path = [blocks[i]['lines'][0] for i in s]
+                path = [blocks[syn]['lines'][0] for syn in s]
                 real = s[-1] + 2
                 realline = blocks[real]['lines']
                 realline[0] = ('"%s"' %