diff --git a/Tools/px_romfs_pruner.py b/Tools/px_romfs_pruner.py
index 5ac8fc2801..fa48019bd0 100644
--- a/Tools/px_romfs_pruner.py
+++ b/Tools/px_romfs_pruner.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 ############################################################################
 #
-#   Copyright (C) 2014-2015 PX4 Development Team. All rights reserved.
+#   Copyright (C) 2014-2016 PX4 Development Team. All rights reserved.
 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -35,7 +35,12 @@
 
 """
 px_romfs_pruner.py:
-Delete all comments and newlines before ROMFS is converted to an image
+Try to keep size of ROMFS minimal.
+
+This script goes through the temporarily copied ROMFS data and deletes all
+comments, empty lines and leading whitespace.
+It also deletes hidden files such as auto-saved backups that a text editor
+might have left in the tree.
 
 @author: Julian Oes <julian@oes.ch>
 """
@@ -53,18 +58,20 @@ def main():
                         help="ROMFS scratch folder.")
     args = parser.parse_args()
 
-    #print("Pruning ROMFS files.")
-
-    # go through
+    # go through temp folder
     for (root, dirs, files) in os.walk(args.folder):
         for file in files:
-            # only prune text files
-            if ".zip" in file or ".bin" in file or ".swp" in file \
-                    or ".data" in file or ".DS_Store" in file \
-                    or file.startswith("."):
+            file_path = os.path.join(root, file)
+
+            # delete hidden files
+            if file.startswith("."):
+                os.remove(file_path)
                 continue
 
-            file_path = os.path.join(root, file)
+            # only prune text files
+            if ".zip" in file or ".bin" in file or ".swp" in file \
+                    or ".data" in file or ".DS_Store" in file:
+                continue
 
             # read file line by line
             pruned_content = ""
@@ -77,7 +84,7 @@ def main():
                     else:
                         if not line.isspace() \
                                 and not line.strip().startswith("#"):
-                            pruned_content += line
+                            pruned_content += line.strip() + "\n"
             # overwrite old scratch file
             with open(file_path, "wb") as f:
                 pruned_content = re.sub("\r\n", "\n", pruned_content)