diff --git a/geomagio/imfv283/GOESIMFV283Factory.py b/geomagio/imfv283/GOESIMFV283Factory.py
index 826ea0b1903fe6a5e98f8195f252225f9c7528b8..474c321492b9bb904ec6c9c0123ee1d1a1378cf1 100644
--- a/geomagio/imfv283/GOESIMFV283Factory.py
+++ b/geomagio/imfv283/GOESIMFV283Factory.py
@@ -1,5 +1,5 @@
 """Factory to load IMFV283 files from an input StreamIMFV283Factory."""
-from __future__ import absolute_import, print_function
+from __future__ import absolute_import, print_function, unicode_literals
 
 from .IMFV283Factory import IMFV283Factory
 import subprocess
@@ -186,5 +186,5 @@ class GOESIMFV283Factory(IMFV283Factory):
         if not os.path.exists(criteria_dir):
             os.makedirs(criteria_dir)
         with open(criteria_file, 'wb') as fh:
-            fh.write(''.join(buf))
+            fh.write(''.join(buf).encode())
             fh.close()