--- a/mercurial/ui.py
+++ b/mercurial/ui.py
@@ -309,7 +309,7 @@ class ui(object):
         sections.sort()
         for section in sections:
             for name, value in self.configitems(section, untrusted):
-                yield section, name, value.replace('\n', '\\n')
+                yield section, name, str(value).replace('\n', '\\n')
 
     def extensions(self):
         result = self.configitems("extensions")

--- a/tests/test-hook
+++ b/tests/test-hook
@@ -203,4 +203,6 @@ hg ci -m 'add foo'
 echo >> foo
 hg ci --debug -m 'change foo' | sed -e 's/ at .*>/>/'
 
+hg showconfig hooks | sed -e 's/ at .*>/>/'
+
 exit 0

--- a/tests/test-hook.out
+++ b/tests/test-hook.out
@@ -142,3 +142,4 @@ Automatically installed hook
 foo
 calling hook commit.auto: <function autohook>
 Automatically installed hook
+hooks.commit.auto=<function autohook>