if files is null, check 'changed' element instead (svn)
diff --git a/commitbot.py b/commitbot.py
index 675dbb3..c485781 100644
--- a/commitbot.py
+++ b/commitbot.py
@@ -53,7 +53,7 @@
     if not commit:  # Probably a still-alive ping, ignore
         return "", ""
     commit_type = commit.get("repository")
-    commit_root, commit_files = files_touched(commit.get("files"))
+    commit_root, commit_files = files_touched(commit.get("files") or commit.get("changed", {}))
     if commit_type == "git":
         commit_subject = commit.get("subject")
         author = commit.get("email", "unknown@apache.org")