diff --git a/pym/install/distr.py b/pym/install/distr.py
index 15a901c..ce3f7a6 100644
--- a/pym/install/distr.py
+++ b/pym/install/distr.py
@@ -118,7 +118,7 @@ def progressCopyFile(source, dest):
     size = int(os.lstat(source).st_size)
     bufsize = (100 - (size % 100) + size) // 100
     with open(source, 'rb') as infile:
-        with open(dest, 'w') as outfile:
+        with open(dest, 'wb') as outfile:
             for i in range(1, 101):
                 outfile.write(infile.read(bufsize))
                 yield i