diff --git a/src/com/fsck/k9/mail/internet/MimeBodyPart.java b/src/com/fsck/k9/mail/internet/MimeBodyPart.java
index 4307b6efb..d3a0ba63d 100644
--- a/src/com/fsck/k9/mail/internet/MimeBodyPart.java
+++ b/src/com/fsck/k9/mail/internet/MimeBodyPart.java
@@ -100,7 +100,7 @@ public class MimeBodyPart extends BodyPart
         }
         else
         {
-            return contentType.toLowerCase();
+            return contentType;
         }
     }