diff --git a/hgext3rd/undo.py b/hgext3rd/undo.py
--- a/hgext3rd/undo.py
+++ b/hgext3rd/undo.py
@@ -626,7 +626,7 @@
             rlog = _getrevlog(repo, 'index.i')
             rev = rlog.rev(bin(hexnode))
             shiftedindex = _invertindex(rlog, rev)
-        except IOError, error.RevlogError:
+        except (IOError, error.RevlogError):
             # no shift
             shiftedindex = 0
             oldbranch = ""
diff --git a/tests/test-undo.t b/tests/test-undo.t
--- a/tests/test-undo.t
+++ b/tests/test-undo.t
@@ -689,7 +689,7 @@
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > strip =
-  > fbamend =
+  > fbamend = $TESTDIR/../hgext3rd/fbamend/
   > EOF
   $ hg strip 3ee6
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved