diff --git a/unbundle.py b/unbundle.py
index 27a1b3c..db095a2 100755
--- a/unbundle.py
+++ b/unbundle.py
@@ -2,17 +2,20 @@ import argparse
 import os
 import sys
 
-def resolve_includes(bundle_name, bundle_path, content, bundles=False, path=set(), seen=set()):
+
+def resolve_includes(bundle_name, bundle_path,
+                     content, bundles=False, seen=None):
     """
     resolve_incudes returns a full package list of include-resolved packages in
     the bundle definition file or pundle declaration under bundle_path. Sources
     for included bundles are other bundle definition files at
     bundle_path/bundles/* and bundle_path/packages.
     """
+    if not seen:
+        seen = set()
     if bundle_name in seen:
         return True
     seen.add(bundle_name)
-    path.add(bundle_name)
     bundle_def = os.path.join(bundle_path, "bundles", bundle_name)
     try:
         with open(bundle_def, "r", encoding="latin-1") as bundlef:
@@ -28,24 +31,23 @@ def resolve_includes(bundle_name, bundle_path, content, bundles=False, path=set(
         line = line.split("#", 1)[0].strip()
         if not line:
             continue
-        elif line.startswith("also-add("):
+        if line.startswith("also-add("):
             continue
-        elif line.startswith("include("):
+        if line.startswith("include("):
             inc_bundle = line[line.find("(")+1:line.find(")")]
-            if inc_bundle in path:
-                return True
-            success = resolve_includes(inc_bundle, bundle_path, content, bundles, path)
+            success = resolve_includes(inc_bundle, bundle_path,
+                                       content, bundles, seen)
             if not success:
                 return False
             if bundles:
                 content.add(inc_bundle)
             continue
-        elif not bundles:
+        if not bundles:
             content.add(line)
 
-    path.remove(bundle_name)
     return True
 
+
 def main():
     parser = argparse.ArgumentParser(description='Process bundle packages following includes')
     parser.add_argument('bundle_name', help='name of bundle to process')
@@ -63,11 +65,13 @@ def main():
     if not success:
         sys.exit(1)
 
-    success = resolve_includes(args.bundle_name, args.bundle_path, content, bundles=args.bundles)
+    success = resolve_includes(args.bundle_name, args.bundle_path, content,
+                               bundles=args.bundles)
     if not success:
         sys.exit(1)
 
     print('\n'.join(sorted(os_core_set.union(content))))
 
+
 if __name__ == "__main__":
     main()