diff --git a/tests/store/base.py b/tests/store/base.py
index 541b633..fc61945 100644
--- a/tests/store/base.py
+++ b/tests/store/base.py
@@ -27,6 +27,7 @@ import operator
 from uuid import uuid4
 import weakref
 
+from storm.base import Storm
 from storm.references import Reference, ReferenceSet, Proxy
 from storm.database import Result, STATE_DISCONNECTED
 from storm.properties import (
@@ -131,6 +132,20 @@ class Money(object):
     value = Decimal()
 
 
+class Customer(Storm):
+    __storm_table__ = 'customer'
+    id = Int(primary=True)
+    email = Unicode()
+    tag = Unicode()
+
+
+class Purchase(Storm):
+    __storm_table__ = 'purchase'
+    id = Int(primary=True)
+    custid = Unicode()
+    customer = Reference(custid, Customer.email)
+
+
 class DecorateVariable(Variable):
 
     def parse_get(self, value, to_db):
@@ -267,7 +282,7 @@ class StoreTest(object):
 
     def drop_tables(self):
         for table in ["foo", "bar", "bin", "link", "money", "selfref",
-                      "foovalue", "unique_id"]:
+                      "foovalue", "unique_id", "customer", "purchase"]:
             try:
                 self.connection.execute("DROP TABLE %s" % table)
                 self.connection.commit()
@@ -466,6 +481,27 @@ class StoreTest(object):
         self.store.flush()
         self.assertEquals(self.store._event._hooks["flush"], set())
 
+    def test_flush_on_unicode_reference(self):
+        """
+        Fix for bug 1334020 in which a KeyError is sometimes raised.
+        """
+        def runScenario(store, email):
+            customer = store.add(Customer())
+            customer.email = email
+            store.commit()
+
+            purchase = store.add(Purchase())
+            purchase.customer = customer
+
+            store.commit()
+
+            customer = store.find(Customer, Customer.email == email).one()
+            customer = list(store.find(Customer))
+
+        runScenario(self.store, u'foo@foo.com')
+        runScenario(self.store, u'bar@bar.com')
+
+
     def test_mutable_variable_detect_change_from_alive(self):
         """
         Changes in a mutable variable like a L{PickleVariable} are correctly
diff --git a/tests/store/mysql.py b/tests/store/mysql.py
index c90b25b..7a33559 100644
--- a/tests/store/mysql.py
+++ b/tests/store/mysql.py
@@ -79,6 +79,15 @@ class MySQLStoreTest(TestHelper, StoreTest):
         connection.execute("CREATE TABLE unique_id "
                            "(id VARCHAR(36) PRIMARY KEY) "
                            "ENGINE=InnoDB")
+        connection.execute("CREATE TABLE customer ("
+                           "email VARCHAR(50) NOT NULL, "
+                           "id INT PRIMARY KEY AUTO_INCREMENT, "
+                           "tag VARCHAR(50)) "
+                           "ENGINE=InnoDB")
+        connection.execute("CREATE TABLE purchase ("
+                           "id INT PRIMARY KEY AUTO_INCREMENT, "
+                           "custid VARCHAR(50)) "
+                           "ENGINE=InnoDB")
         connection.commit()
 
 
diff --git a/tests/store/postgres.py b/tests/store/postgres.py
index c9ce63e..cdf2788 100644
--- a/tests/store/postgres.py
+++ b/tests/store/postgres.py
@@ -93,6 +93,13 @@ class PostgresStoreTest(TestHelper, StoreTest):
                            " value1 INTEGER, value2 INTEGER)")
         connection.execute("CREATE TABLE unique_id "
                            "(id UUID PRIMARY KEY)")
+        connection.execute("CREATE TABLE customer ("
+                           "email TEXT NOT NULL, "
+                           "id SERIAL PRIMARY KEY, "
+                           "tag TEXT)")
+        connection.execute("CREATE TABLE purchase ("
+                           "id SERIAL PRIMARY KEY, "
+                           "custid TEXT)")
         connection.commit()
 
     def drop_tables(self):
diff --git a/tests/store/sqlite.py b/tests/store/sqlite.py
index 51fcc51..9315a8e 100644
--- a/tests/store/sqlite.py
+++ b/tests/store/sqlite.py
@@ -65,6 +65,13 @@ class SQLiteStoreTest(TestHelper, StoreTest):
                            " value1 INTEGER, value2 INTEGER)")
         connection.execute("CREATE TABLE unique_id "
                            "(id VARCHAR PRIMARY KEY)")
+        connection.execute("CREATE TABLE customer ("
+                           "email TEXT NOT NULL, "
+                           "id INTEGER PRIMARY KEY, "
+                           "tag TEXT)")
+        connection.execute("CREATE TABLE purchase ("
+                           "id INTEGER PRIMARY KEY, "
+                           "custid TEXT)")
         connection.commit()
 
     def drop_tables(self):