diff --git a/utils/build_data_tre.py b/utils/build_data_tre.py
index 6a80b4c..c2f2ae9 100755
--- a/utils/build_data_tre.py
+++ b/utils/build_data_tre.py
@@ -9,7 +9,6 @@ import os.path
 hashes = { }
 newFiles = { }
 
-
 parser = argparse.ArgumentParser()
 parser.add_argument('version', help='version to create, min is 1')
 parser.add_argument('--from', dest='oldVersion', help='version to update from', default="0")
@@ -29,6 +28,9 @@ def isIgnoredDirectory(dir):
 	return False
 
 def addFiles( src ):
+	if not os.path.exists(src):
+		return
+
 	for root, dirs, files in os.walk(src):
 		path = root.split(os.sep)
 
@@ -98,6 +100,7 @@ if args.oldVersion not in "0": loadOldChecksums()
 # add client-only files
 addFiles( "data/sku.0/sys.client/compiled/game/" )
 addFiles( "data/sku.0/sys.client/built/game/" )
+addFiles( "data/sku.0/sys.client/custom/" )
 
 # add shared files
 addFiles( "data/sku.0/sys.shared/compiled/game/" )