1 files changed, 1 insertions, 0 deletions
diff --git a/builder.py b/builder.py
index 6b80f35..fc653ec 100644
--- a/builder.py
+++ b/builder.py
@@ -44,6 +44,7 @@ if sys.version_info >= (3, 0):
     def open_source_file(filename):
         byte_stream = open(filename, 'bU')
         encoding = detect_encoding(byte_stream.readline)[0]
+        byte_stream.close()
         stream = open(filename, 'U', encoding=encoding)
         try:
             data = stream.read()