1 files changed, 1 insertions, 1 deletions
diff --git a/lib/mailread.rb b/lib/mailread.rb
index 8ec951e754..5e46606c09 100644
--- a/lib/mailread.rb
+++ b/lib/mailread.rb
@@ -1,7 +1,7 @@
 class Mail
 
   def initialize(f)
-    unless f.kind_of?(IO)
+    unless defined? f.gets
       f = open(f, "r")
       opened = true
     end