diff --git a/anki/importing/noteimp.py b/anki/importing/noteimp.py
index df74a41f1..fe8c7d853 100644
--- a/anki/importing/noteimp.py
+++ b/anki/importing/noteimp.py
@@ -115,10 +115,11 @@ class NoteImporter(Importer):
                 for id in csums[csum]:
                     flds = self.col.db.scalar(
                         "select flds from notes where id = ?", id)
-                    if fld0 == splitFields(flds)[0]:
+                    sflds = splitFields(flds)
+                    if fld0 == sflds[0]:
                         # duplicate
                         if self.update:
-                            data = self.updateData(n, id)
+                            data = self.updateData(n, id, sflds)
                             if data:
                                 updates.append(data)
                         # note that we've seen this note once already
@@ -162,9 +163,9 @@ class NoteImporter(Importer):
             rows)
 
     # need to document that deck is ignored in this case
-    def updateData(self, n, id):
+    def updateData(self, n, id, sflds):
         self._ids.append(id)
-        if not self.processFields(n):
+        if not self.processFields(n, sflds):
             print "no cards generated"
             return
         self.col.tags.register(n.tags)
@@ -177,8 +178,9 @@ class NoteImporter(Importer):
 update notes set mod = ?, usn = ?, flds = ?, tags = ?
 where id = ? and (flds != ? or tags != ?)""", rows)
 
-    def processFields(self, note):
-        fields = [""]*len(self.model['flds'])
+    def processFields(self, note, fields=None):
+        if not fields:
+            fields = [""]*len(self.model['flds'])
         for c, f in enumerate(self.mapping):
             if not f:
                 continue
diff --git a/tests/support/text-update.txt b/tests/support/text-update.txt
index f87113172..5253c89d1 100644
--- a/tests/support/text-update.txt
+++ b/tests/support/text-update.txt
@@ -1,11 +1 @@
-# this is a test file
-
-食べる	to ate
-む	to drink
-テスト	testing
-to eat	食べる
-飲む	to drink
-多すぎる	too many	fields
-not, enough, fields
-遊ぶ	
-	to play
+1	x
diff --git a/tests/test_importing.py b/tests/test_importing.py
index c5170961c..5422065a2 100644
--- a/tests/test_importing.py
+++ b/tests/test_importing.py
@@ -96,6 +96,29 @@ def test_csv():
     assert i.total == 0
     deck.close()
 
+def test_csv2():
+    deck = getEmptyDeck()
+    mm = deck.models
+    m = mm.current()
+    f = mm.newField("Three")
+    mm.addField(m, f)
+    mm.save(m)
+    n = deck.newNote()
+    n['Front'] = "1"
+    n['Back'] = "2"
+    n['Three'] = "3"
+    deck.addNote(n)
+    # an update with unmapped fields should not clobber those fields
+    file = unicode(os.path.join(testDir, "support/text-update.txt"))
+    i = TextImporter(deck, file)
+    i.initMapping()
+    i.run()
+    n.load()
+    assert n['Front'] == "1"
+    assert n['Back'] == "x"
+    assert n['Three'] == "3"
+    deck.close()
+
 def test_supermemo_xml_01_unicode():
     deck = getEmptyDeck()
     file = unicode(os.path.join(testDir, "support/supermemo1.xml"))