diff --git a/src/python/jw/pkg/App.py b/src/python/jw/pkg/App.py
index dabb97ef..8a67dc3e 100644
--- a/src/python/jw/pkg/App.py
+++ b/src/python/jw/pkg/App.py
@@ -590,6 +590,7 @@ class App(Base):
         if isinstance(keys, str):
             keys = [keys]
         ret: list[str] = []
+        seen: set[str] = set()
         for key in keys:
             visited: set[str] = set()
             for name in projects:
@@ -597,9 +598,9 @@ class App(Base):
                 self.walk_project_deps(
                     rr, visited, name, sections, key, add_self, scope, names_only
                 )
-                # TODO: this looks like a performance hogger
                 for m in rr:
-                    if m not in ret:
+                    if m not in seen:
+                        seen.add(m)
                         ret.append(m)
         return ret