diff --git a/python/bifrost/block.py b/python/bifrost/block.py
index 67376f0fa..2044b65ec 100644
--- a/python/bifrost/block.py
+++ b/python/bifrost/block.py
@@ -571,6 +571,7 @@ def main(self, input_ring):
                 data_accumulate = unpacked_data[0]
         text_file = open(self.filename, 'a')
         np.savetxt(text_file, data_accumulate.reshape((1, -1)))
+        text_file.close()
 class CopyBlock(TransformBlock):
     """Copies input ring's data to the output ring"""
     def __init__(self, gulp_size=1048576):