diff --git a/anki/storage.py b/anki/storage.py
index 59f5ac130..92d470842 100644
--- a/anki/storage.py
+++ b/anki/storage.py
@@ -511,12 +511,16 @@ def _fixupModels(deck):
     # rewrite model/template/field ids
     models = deck.models()
     deck.db.execute("delete from models")
+    times = {}
     for c, m in enumerate(models.values()):
         # update ordinals
         m._updateFieldOrds()
         m._updateTemplOrds()
         # we've temporarily stored the model creation time in the mod time
         old = m.id
+        while m.mod in times:
+            m.mod += 1
+        times[m.mod] = True
         m.id = m.mod
         m.mod = intTime()
         m.flush()
diff --git a/tests/support/anki12.anki b/tests/support/anki12.anki
index 3ee5fe744..042ecf4f4 100644
Binary files a/tests/support/anki12.anki and b/tests/support/anki12.anki differ