diff --git a/anki/importing/__init__.py b/anki/importing/__init__.py
index fc601ca6e..71a0ebd51 100644
--- a/anki/importing/__init__.py
+++ b/anki/importing/__init__.py
@@ -341,12 +341,10 @@ where factId in (%s)""" % ",".join([str(s) for s in factIds]))
 
 from anki.importing.csvfile import TextImporter
 from anki.importing.anki10 import Anki10Importer
-from anki.importing.mnemosyne10 import Mnemosyne10Importer
 from anki.importing.supermemo_xml import SupermemoXmlImporter
 
 Importers = (
     (_("Text separated by tabs or semicolons (*)"), TextImporter),
     (_("Anki Deck (*.anki)"), Anki10Importer),
-    (_("Mnemosyne Deck (*.mem)"), Mnemosyne10Importer),
     (_("Supermemo XML export (*.xml)"), SupermemoXmlImporter),
     )
diff --git a/anki/migration/__init__.py b/anki/migration/__init__.py
deleted file mode 100644
index ea8ce5786..000000000
--- a/anki/migration/__init__.py
+++ /dev/null
@@ -1,8 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright: Damien Elmes <anki@ichi2.net>
-# License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
-
-class Migrator(object):
-
-    def __init__(self, deck):
-        pass
diff --git a/anki/migration/checker.py b/anki/migration/checker.py
deleted file mode 100644
index 43bb98f96..000000000
--- a/anki/migration/checker.py
+++ /dev/null
@@ -1,68 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright: Damien Elmes <anki@ichi2.net>
-# License: GNU AGPL, version 3 or later; http://www.gnu.org/copyleft/agpl.html
-
-from anki.db import DB
-
-def check(path):
-    "True if deck looks ok."
-    db = DB(path)
-    # corrupt?
-    try:
-        if db.scalar("pragma integrity_check") != "ok":
-            return
-    except:
-        return
-    # old version?
-    if db.scalar("select version from decks") != 65:
-        return
-    # fields missing a field model?
-    if db.list("""
-select id from fields where fieldModelId not in (
-select distinct id from fieldModels)"""):
-        return
-    # facts missing a field?
-    if db.list("""
-select distinct facts.id from facts, fieldModels where
-facts.modelId = fieldModels.modelId and fieldModels.id not in
-(select fieldModelId from fields where factId = facts.id)"""):
-        return
-    # cards missing a fact?
-    if db.list("""
-select id from cards where factId not in (select id from facts)"""):
-        return
-    # cards missing a card model?
-    if db.list("""
-select id from cards where cardModelId not in
-(select id from cardModels)"""):
-        return
-    # cards with a card model from the wrong model?
-    if db.list("""
-select id from cards where cardModelId not in (select cm.id from
-cardModels cm, facts f where cm.modelId = f.modelId and
-f.id = cards.factId)"""):
-        return
-    # facts missing a card?
-    if db.list("""
-select facts.id from facts
-where facts.id not in (select distinct factId from cards)"""):
-        return
-    # dangling fields?
-    if db.list("""
-select id from fields where factId not in (select id from facts)"""):
-        return
-    # fields without matching interval
-    if db.list("""
-select id from fields where ordinal != (select ordinal from fieldModels
-where id = fieldModelId)"""):
-        return
-    # incorrect types
-    if db.list("""
-select id from cards where relativeDelay != (case
-when successive then 1 when reps then 0 else 2 end)"""):
-        return
-    if db.list("""
-select id from cards where type != (case
-when type >= 0 then relativeDelay else relativeDelay - 3 end)"""):
-        return
-    return True
diff --git a/anki/migration/upgrader.py b/anki/upgrade.py
similarity index 84%
rename from anki/migration/upgrader.py
rename to anki/upgrade.py
index 60bb657b9..f13d00364 100644
--- a/anki/migration/upgrader.py
+++ b/anki/upgrade.py
@@ -14,9 +14,9 @@ from anki.storage import _addSchema, _getDeckVars, _addDeckVars, \
 #
 # Upgrading is the first step in migrating to 2.0. The ids are temporary and
 # may not be unique across multiple decks. After each of a user's v1.2 decks
-# are upgraded, they need to be merged.
+# are upgraded, they need to be merged via the import code.
 #
-# Caller should have called check() on path before using this.
+# Caller should have called check() on path before calling upgrade().
 #
 
 class Upgrader(object):
@@ -24,6 +24,9 @@ class Upgrader(object):
     def __init__(self):
         pass
 
+    # Upgrading
+    ######################################################################
+
     def upgrade(self, path):
         self.path = path
         self._openDB(path)
@@ -32,6 +35,78 @@ class Upgrader(object):
         self._upgradeDeck()
         return self.deck
 
+    # Integrity checking
+    ######################################################################
+
+    def check(self, path):
+        "True if deck looks ok."
+        with DB(path) as db:
+            return self._check(db)
+
+    def _check(self, db):
+        # corrupt?
+        try:
+            if db.scalar("pragma integrity_check") != "ok":
+                return
+        except:
+            return
+        # old version?
+        if db.scalar("select version from decks") != 65:
+            return
+        # fields missing a field model?
+        if db.list("""
+    select id from fields where fieldModelId not in (
+    select distinct id from fieldModels)"""):
+            return
+        # facts missing a field?
+        if db.list("""
+    select distinct facts.id from facts, fieldModels where
+    facts.modelId = fieldModels.modelId and fieldModels.id not in
+    (select fieldModelId from fields where factId = facts.id)"""):
+            return
+        # cards missing a fact?
+        if db.list("""
+    select id from cards where factId not in (select id from facts)"""):
+            return
+        # cards missing a card model?
+        if db.list("""
+    select id from cards where cardModelId not in
+    (select id from cardModels)"""):
+            return
+        # cards with a card model from the wrong model?
+        if db.list("""
+    select id from cards where cardModelId not in (select cm.id from
+    cardModels cm, facts f where cm.modelId = f.modelId and
+    f.id = cards.factId)"""):
+            return
+        # facts missing a card?
+        if db.list("""
+    select facts.id from facts
+    where facts.id not in (select distinct factId from cards)"""):
+            return
+        # dangling fields?
+        if db.list("""
+    select id from fields where factId not in (select id from facts)"""):
+            return
+        # fields without matching interval
+        if db.list("""
+    select id from fields where ordinal != (select ordinal from fieldModels
+    where id = fieldModelId)"""):
+            return
+        # incorrect types
+        if db.list("""
+    select id from cards where relativeDelay != (case
+    when successive then 1 when reps then 0 else 2 end)"""):
+            return
+        if db.list("""
+    select id from cards where type != (case
+    when type >= 0 then relativeDelay else relativeDelay - 3 end)"""):
+            return
+        return True
+
+    # DB/Deck opening
+    ######################################################################
+
     def _openDB(self, path):
         self.tmppath = namedtmp(os.path.basename(path))
         shutil.copy(path, self.tmppath)
diff --git a/tests/test_migration.py b/tests/test_upgrade.py
similarity index 81%
rename from tests/test_migration.py
rename to tests/test_upgrade.py
index 2d36586cc..e1d66d19a 100644
--- a/tests/test_migration.py
+++ b/tests/test_upgrade.py
@@ -3,15 +3,15 @@
 import datetime
 from anki.consts import *
 from shared import getUpgradeDeckPath
-from anki.migration.checker import check
-from anki.migration.upgrader import Upgrader
+from anki.upgrade import Upgrader
 
-def test_checker():
+def test_check():
     dst = getUpgradeDeckPath()
-    assert check(dst)
+    u = Upgrader()
+    assert u.check(dst)
     # if it's corrupted, will fail
     open(dst, "w+").write("foo")
-    assert not check(dst)
+    assert not u.check(dst)
 
 def test_upgrade():
     dst = getUpgradeDeckPath()