diff --git a/tracopt/versioncontrol/svn/svn_fs.py b/tracopt/versioncontrol/svn/svn_fs.py
index b2c8233b10..f4b53839dd 100644
--- a/tracopt/versioncontrol/svn/svn_fs.py
+++ b/tracopt/versioncontrol/svn/svn_fs.py
@@ -256,6 +256,9 @@ def db_rev(self, rev):
     def rev_db(self, rev):
         return int(rev or 0)
 
+    def normalize_rev(self, rev):
+        return self.repos.normalize_rev(rev)
+
 
 class SubversionConnector(Component):
 
@@ -427,7 +430,7 @@ def normalize_rev(self, rev):
         else:
             try:
                 rev = int(rev)
-                if rev <= self.youngest_rev:
+                if 0 <= rev <= self.youngest_rev:
                     return rev
             except (ValueError, TypeError):
                 pass
@@ -766,7 +769,7 @@ def __init__(self, path, rev, repos, pool=None, parent_root=None):
             try:
                 self.root = fs.revision_root(self.fs_ptr, rev, pool)
             except core.SubversionException as e:
-                raise TracError(e)
+                raise NoSuchChangeset(e)
         node_type = fs.check_path(self.root, self._scoped_path_utf8, pool)
         if not node_type in _kindmap:
             raise NoSuchNode(path, rev)
diff --git a/tracopt/versioncontrol/svn/tests/svn_fs.py b/tracopt/versioncontrol/svn/tests/svn_fs.py
index 488b2f348b..8aea390546 100644
--- a/tracopt/versioncontrol/svn/tests/svn_fs.py
+++ b/tracopt/versioncontrol/svn/tests/svn_fs.py
@@ -130,6 +130,8 @@ def test_repos_normalize_rev(self):
         self.assertEqual(HEAD, self.repos.normalize_rev(None))
         self.assertEqual(11, self.repos.normalize_rev('11'))
         self.assertEqual(11, self.repos.normalize_rev(11))
+        self.assertRaises(NoSuchChangeset, self.repos.normalize_rev, -1)
+        self.assertRaises(NoSuchChangeset, self.repos.normalize_rev, -42)
 
     def test_repos_display_rev(self):
         self.assertEqual(str(HEAD), self.repos.display_rev('latest'))
@@ -189,7 +191,7 @@ def test_get_node(self):
         self.assertEqual(HEAD, node.created_rev)
         self.assertEqual(datetime(2015, 6, 15, 14, 9, 13, 664490, utc),
                          node.last_modified)
-        self.assertRaises(TracError, self.repos.get_node, u'/', -1)
+        self.assertRaises(NoSuchChangeset, self.repos.get_node, u'/', -1)
         node = self.repos.get_node(u'/tête')
         self.assertEqual(u'tête', node.name)
         self.assertEqual(u'/tête', node.path)