diff --git a/nav2_common/nav2_common/launch/rewritten_yaml.py b/nav2_common/nav2_common/launch/rewritten_yaml.py
index 63d3905d5e..3b29fdda59 100644
--- a/nav2_common/nav2_common/launch/rewritten_yaml.py
+++ b/nav2_common/nav2_common/launch/rewritten_yaml.py
@@ -161,7 +161,7 @@ def pathify(self, d, p=None, paths=None, joinchar='.'):
         if isinstance(d, dict):
             for k in d:
                 v = d[k]
-                self.pathify(v, pn + k, paths, joinchar=joinchar)
+                self.pathify(v, str(pn) + str(k), paths, joinchar=joinchar)
         elif isinstance(d, list):
             for idx, e in enumerate(d):
                 self.pathify(e, pn + str(idx), paths, joinchar=joinchar)