diff --git a/Lib/quopri.py b/Lib/quopri.py
index 5f5e80c..e7e4bec 100755
--- a/Lib/quopri.py
+++ b/Lib/quopri.py
@@ -65,7 +65,7 @@
         if n > 0 and line[n-1] == '\n':
             partial = 0; n = n-1
             # Strip trailing whitespace
-            while n > 0 and line[n-1] in (' ', '\t'):
+            while n > 0 and line[n-1] in " \t\r":
                 n = n-1
         else:
             partial = 1