diff --git a/py/makeqstrdefs.py b/py/makeqstrdefs.py
index bdc432d7d..8e930ef50 100644
--- a/py/makeqstrdefs.py
+++ b/py/makeqstrdefs.py
@@ -138,15 +138,12 @@ def cat_together():
 
     hasher = hashlib.md5()
     all_lines = []
-    outf = open(args.output_dir + "/out", "wb")
     for fname in glob.glob(args.output_dir + "/*." + args.mode):
         with open(fname, "rb") as f:
             lines = f.readlines()
             all_lines += lines
     all_lines.sort()
     all_lines = b"\n".join(all_lines)
-    outf.write(all_lines)
-    outf.close()
     hasher.update(all_lines)
     new_hash = hasher.hexdigest()
     # print(new_hash)
@@ -165,12 +162,9 @@ def cat_together():
         mode_full = "Root pointer registrations"
     if old_hash != new_hash or not os.path.exists(args.output_file):
         print(mode_full, "updated")
-        try:
-            # rename below might fail if file exists
-            os.remove(args.output_file)
-        except:
-            pass
-        os.rename(args.output_dir + "/out", args.output_file)
+
+        with open(args.output_file, "wb") as outf:
+            outf.write(all_lines)
         with open(args.output_file + ".hash", "w") as f:
             f.write(new_hash)
     else: