diff --git a/src/com/fsck/k9/mail/internet/MimeUtility.java b/src/com/fsck/k9/mail/internet/MimeUtility.java
index 42033eda1..32a8b1679 100644
--- a/src/com/fsck/k9/mail/internet/MimeUtility.java
+++ b/src/com/fsck/k9/mail/internet/MimeUtility.java
@@ -1183,16 +1183,16 @@ public class MimeUtility {
         // If the MIME type set by the user's mailer is application/octet-stream, try to figure
         // out whether there's a sane file type extension.
         if (returnedType != null && !DEFAULT_ATTACHMENT_MIME_TYPE.equalsIgnoreCase(returnedType)) {
-            return getCorrectedMimeType(returnedType);
+            return returnedType;
         } else if (extension != null) {
             for (String[] contentTypeMapEntry : MIME_TYPE_BY_EXTENSION_MAP) {
                 if (contentTypeMapEntry[0].equals(extension)) {
-                    return getCorrectedMimeType(contentTypeMapEntry[1]);
+                    return contentTypeMapEntry[1];
                 }
             }
         }
 
-        return getCorrectedMimeType(DEFAULT_ATTACHMENT_MIME_TYPE);
+        return DEFAULT_ATTACHMENT_MIME_TYPE;
     }
     
     /**
@@ -1202,7 +1202,7 @@ public class MimeUtility {
      * @param mimeType the MIME type
      * @return the corrected MIME type
      */
-    public static String getCorrectedMimeType(String mimeType) {
+    public static String canonicalizeMimeType(String mimeType) {
 		for (String[] mimeTypeMapEntry : MIME_TYPE_REPLACEMENT_MAP) {
 			if (mimeTypeMapEntry[0].equals(mimeType)) {
 				return mimeTypeMapEntry[1];
diff --git a/src/com/fsck/k9/mail/store/LocalStore.java b/src/com/fsck/k9/mail/store/LocalStore.java
index 7141d18c4..e90e5a64e 100644
--- a/src/com/fsck/k9/mail/store/LocalStore.java
+++ b/src/com/fsck/k9/mail/store/LocalStore.java
@@ -1010,7 +1010,7 @@ public class LocalStore extends Store implements Serializable {
                     if (MimeUtility.DEFAULT_ATTACHMENT_MIME_TYPE.equalsIgnoreCase(type)) {
                         type = MimeUtility.getMimeTypeByExtension(name);
                     }
-                    return MimeUtility.getCorrectedMimeType(type);
+                    return type;
                 } finally {
                     if (cursor != null) {
                         cursor.close();
diff --git a/src/com/fsck/k9/provider/AttachmentProvider.java b/src/com/fsck/k9/provider/AttachmentProvider.java
index 90ac52c89..5deeecd61 100644
--- a/src/com/fsck/k9/provider/AttachmentProvider.java
+++ b/src/com/fsck/k9/provider/AttachmentProvider.java
@@ -105,7 +105,7 @@ public class AttachmentProvider extends ContentProvider {
 
             try {
                 final LocalStore localStore = LocalStore.getLocalInstance(account, K9.app);
-                return localStore.getAttachmentType(id);
+                return MimeUtility.canonicalizeMimeType(localStore.getAttachmentType(id));
                
             } catch (MessagingException e) {
                 Log.e(K9.LOG_TAG, "Unable to retrieve LocalStore for " + account, e);