diff --git a/Lib/email/base64MIME.py b/Lib/email/base64MIME.py
index 11979e359ec..aada22d0e2f 100644
--- a/Lib/email/base64MIME.py
+++ b/Lib/email/base64MIME.py
@@ -87,7 +87,7 @@ def header_encode(header, charset='iso-8859-1', keep_eols=0, maxlinelen=76,
     # length, after the RFC chrome is added in.
     base64ed = []
     max_encoded = maxlinelen - len(charset) - MISC_LEN
-    max_unencoded = max_encoded * 3 / 4
+    max_unencoded = max_encoded * 3 // 4
 
     # BAW: Ben's original code used a step of max_unencoded, but I think it
     # ought to be max_encoded.  Otherwise, where's max_encoded used?  I'm
@@ -131,7 +131,7 @@ def encode(s, binary=1, maxlinelen=76, eol=NL):
         s = fix_eols(s)
 
     encvec = []
-    max_unencoded = maxlinelen * 3 / 4
+    max_unencoded = maxlinelen * 3 // 4
     for i in range(0, len(s), max_unencoded):
         # BAW: should encode() inherit b2a_base64()'s dubious behavior in
         # adding a newline to the encoded string?