diff --git a/core/src/test/java/google/registry/flows/contact/ContactUpdateFlowTest.java b/core/src/test/java/google/registry/flows/contact/ContactUpdateFlowTest.java
index b86a4d067..c16d19e8c 100644
--- a/core/src/test/java/google/registry/flows/contact/ContactUpdateFlowTest.java
+++ b/core/src/test/java/google/registry/flows/contact/ContactUpdateFlowTest.java
@@ -42,12 +42,19 @@ import google.registry.model.contact.PostalInfo;
 import google.registry.model.contact.PostalInfo.Type;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.testing.DualDatabaseTest;
+import google.registry.testing.ReplayExtension;
 import google.registry.testing.TestOfyAndSql;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link ContactUpdateFlow}. */
 @DualDatabaseTest
 class ContactUpdateFlowTest extends ResourceFlowTestCase<ContactUpdateFlow, ContactResource> {
 
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   ContactUpdateFlowTest() {
     setEppInput("contact_update.xml");
   }
diff --git a/core/src/test/java/google/registry/flows/domain/DomainCheckFlowTest.java b/core/src/test/java/google/registry/flows/domain/DomainCheckFlowTest.java
index 18fbccfab..a481aa21e 100644
--- a/core/src/test/java/google/registry/flows/domain/DomainCheckFlowTest.java
+++ b/core/src/test/java/google/registry/flows/domain/DomainCheckFlowTest.java
@@ -72,6 +72,7 @@ import google.registry.model.registry.Registry.TldState;
 import google.registry.model.registry.label.ReservedList;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.testing.ReplayExtension;
+import google.registry.testing.SetClockExtension;
 import org.joda.money.CurrencyUnit;
 import org.joda.money.Money;
 import org.joda.time.DateTime;
@@ -79,8 +80,6 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.BeforeEachCallback;
-import org.junit.jupiter.api.extension.ExtensionContext;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link DomainCheckFlow}. */
@@ -88,7 +87,7 @@ class DomainCheckFlowTest extends ResourceCheckFlowTestCase<DomainCheckFlow, Dom
 
   @Order(value = Order.DEFAULT - 3)
   @RegisterExtension
-  final SetClockExtension setClockExtension = new SetClockExtension();
+  final SetClockExtension setClockExtension = new SetClockExtension(clock, "2009-01-01T10:00:00Z");
 
   @Order(value = Order.DEFAULT - 2)
   @RegisterExtension
@@ -1351,12 +1350,4 @@ class DomainCheckFlowTest extends ResourceCheckFlowTestCase<DomainCheckFlow, Dom
             .setStatusValues(ImmutableSet.of(StatusValue.PENDING_DELETE))
             .build());
   }
-
-  class SetClockExtension implements BeforeEachCallback {
-    @Override
-    public void beforeEach(ExtensionContext context) {
-      // Kick the clock back to before the earliest date that we set the clock to.
-      clock.setTo(DateTime.parse("2009-01-01T10:00:00Z"));
-    }
-  }
 }
diff --git a/core/src/test/java/google/registry/flows/domain/DomainInfoFlowTest.java b/core/src/test/java/google/registry/flows/domain/DomainInfoFlowTest.java
index dd550111f..66cc56ed0 100644
--- a/core/src/test/java/google/registry/flows/domain/DomainInfoFlowTest.java
+++ b/core/src/test/java/google/registry/flows/domain/DomainInfoFlowTest.java
@@ -66,12 +66,11 @@ import google.registry.model.reporting.HistoryEntry;
 import google.registry.persistence.VKey;
 import google.registry.testing.AppEngineExtension;
 import google.registry.testing.ReplayExtension;
+import google.registry.testing.SetClockExtension;
 import org.joda.time.DateTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.BeforeEachCallback;
-import org.junit.jupiter.api.extension.ExtensionContext;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link DomainInfoFlow}. */
@@ -79,7 +78,8 @@ class DomainInfoFlowTest extends ResourceFlowTestCase<DomainInfoFlow, DomainBase
 
   @Order(value = Order.DEFAULT - 3)
   @RegisterExtension
-  final SetClockExtension setClockExtension = new SetClockExtension();
+  final SetClockExtension setClockExtension =
+      new SetClockExtension(clock, "2005-03-03T22:00:00.000Z");
 
   @Order(value = Order.DEFAULT - 2)
   @RegisterExtension
@@ -973,12 +973,4 @@ class DomainInfoFlowTest extends ResourceFlowTestCase<DomainInfoFlow, DomainBase
     assertIcannReportingActivityFieldLogged("srs-dom-info");
     assertTldsFieldLogged("tld");
   }
-
-  class SetClockExtension implements BeforeEachCallback {
-    @Override
-    public void beforeEach(ExtensionContext context) {
-      // Kick the clock back to before the earliest date that we set the clock to.
-      clock.setTo(DateTime.parse("2005-03-03T22:00:00.000Z"));
-    }
-  }
 }
diff --git a/core/src/test/java/google/registry/flows/domain/DomainRenewFlowTest.java b/core/src/test/java/google/registry/flows/domain/DomainRenewFlowTest.java
index 2fc2a9cf9..184270090 100644
--- a/core/src/test/java/google/registry/flows/domain/DomainRenewFlowTest.java
+++ b/core/src/test/java/google/registry/flows/domain/DomainRenewFlowTest.java
@@ -71,6 +71,7 @@ import google.registry.model.reporting.DomainTransactionRecord;
 import google.registry.model.reporting.DomainTransactionRecord.TransactionReportField;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.testing.ReplayExtension;
+import google.registry.testing.SetClockExtension;
 import java.util.Map;
 import org.joda.money.Money;
 import org.joda.time.DateTime;
@@ -78,8 +79,6 @@ import org.joda.time.Duration;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.BeforeEachCallback;
-import org.junit.jupiter.api.extension.ExtensionContext;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link DomainRenewFlow}. */
@@ -104,7 +103,8 @@ class DomainRenewFlowTest extends ResourceFlowTestCase<DomainRenewFlow, DomainBa
 
   @Order(value = Order.DEFAULT - 3)
   @RegisterExtension
-  final SetClockExtension setClockExtension = new SetClockExtension();
+  final SetClockExtension setClockExtension =
+      new SetClockExtension(clock, expirationTime.minusMillis(20));
 
   @Order(value = Order.DEFAULT - 2)
   @RegisterExtension
@@ -812,21 +812,4 @@ class DomainRenewFlowTest extends ResourceFlowTestCase<DomainRenewFlow, DomainBa
                 TransactionReportField.netRenewsFieldFromYears(5),
                 1));
   }
-
-  /**
-   * Local extension so we can set the clock correctly prior to using it to define basic entities in
-   * AppEngineExtension.
-   *
-   * <p>This has to happen first, we'll get timestamp inversions if we try to set the clock after
-   * these objects are created.
-   */
-  class SetClockExtension implements BeforeEachCallback {
-    @Override
-    public void beforeEach(ExtensionContext context) {
-      // we have to go far enough back before the expiration time so that the clock advances we do
-      // after each persist don't move us into a grace period.  The current value is likely beyond
-      // what is necessary, but this doesn't hurt.
-      clock.setTo(expirationTime.minusMillis(20));
-    }
-  }
 }
diff --git a/core/src/test/java/google/registry/flows/host/HostCreateFlowTest.java b/core/src/test/java/google/registry/flows/host/HostCreateFlowTest.java
index 1e1ee5bcd..1434caed2 100644
--- a/core/src/test/java/google/registry/flows/host/HostCreateFlowTest.java
+++ b/core/src/test/java/google/registry/flows/host/HostCreateFlowTest.java
@@ -55,13 +55,20 @@ import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.host.HostResource;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.testing.DualDatabaseTest;
+import google.registry.testing.ReplayExtension;
 import google.registry.testing.TestOfyAndSql;
 import org.joda.time.DateTime;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link HostCreateFlow}. */
 @DualDatabaseTest
 class HostCreateFlowTest extends ResourceFlowTestCase<HostCreateFlow, HostResource> {
 
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   private void setEppHostCreateInput(String hostName, String hostAddrs) {
     setEppInput(
         "host_create.xml",
diff --git a/core/src/test/java/google/registry/flows/host/HostDeleteFlowTest.java b/core/src/test/java/google/registry/flows/host/HostDeleteFlowTest.java
index afe5ed7a2..dbb6db1c0 100644
--- a/core/src/test/java/google/registry/flows/host/HostDeleteFlowTest.java
+++ b/core/src/test/java/google/registry/flows/host/HostDeleteFlowTest.java
@@ -47,14 +47,21 @@ import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.DomainTransferData;
 import google.registry.model.transfer.TransferStatus;
 import google.registry.testing.DualDatabaseTest;
+import google.registry.testing.ReplayExtension;
 import google.registry.testing.TestOfyAndSql;
 import org.joda.time.DateTime;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link HostDeleteFlow}. */
 @DualDatabaseTest
 class HostDeleteFlowTest extends ResourceFlowTestCase<HostDeleteFlow, HostResource> {
 
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   @BeforeEach
   void initFlowTest() {
     setEppInput("host_delete.xml", ImmutableMap.of("HOSTNAME", "ns1.example.tld"));
diff --git a/core/src/test/java/google/registry/flows/host/HostInfoFlowTest.java b/core/src/test/java/google/registry/flows/host/HostInfoFlowTest.java
index 9fd4f45f4..739aec939 100644
--- a/core/src/test/java/google/registry/flows/host/HostInfoFlowTest.java
+++ b/core/src/test/java/google/registry/flows/host/HostInfoFlowTest.java
@@ -18,6 +18,7 @@ import static com.google.common.truth.Truth.assertThat;
 import static google.registry.testing.DatabaseHelper.assertNoBillingEvents;
 import static google.registry.testing.DatabaseHelper.createTld;
 import static google.registry.testing.DatabaseHelper.newDomainBase;
+import static google.registry.testing.DatabaseHelper.persistNewRegistrar;
 import static google.registry.testing.DatabaseHelper.persistResource;
 import static google.registry.testing.EppExceptionSubject.assertAboutEppExceptions;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -34,14 +35,21 @@ import google.registry.flows.host.HostFlowUtils.HostNameNotPunyCodedException;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.host.HostResource;
+import google.registry.testing.ReplayExtension;
 import javax.annotation.Nullable;
 import org.joda.time.DateTime;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link HostInfoFlow}. */
 class HostInfoFlowTest extends ResourceFlowTestCase<HostInfoFlow, HostResource> {
 
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   HostInfoFlowTest() {
     setEppInput("host_info.xml", ImmutableMap.of("HOSTNAME", "ns1.example.tld"));
   }
@@ -105,6 +113,7 @@ class HostInfoFlowTest extends ResourceFlowTestCase<HostInfoFlow, HostResource>
 
   private void runTest_superordinateDomain(
       DateTime domainTransferTime, @Nullable DateTime lastSuperordinateChange) throws Exception {
+    persistNewRegistrar("superclientid");
     DomainBase domain =
         persistResource(
             newDomainBase("parent.foobar")
diff --git a/core/src/test/java/google/registry/flows/host/HostUpdateFlowTest.java b/core/src/test/java/google/registry/flows/host/HostUpdateFlowTest.java
index 8a81a3e04..6bda395ee 100644
--- a/core/src/test/java/google/registry/flows/host/HostUpdateFlowTest.java
+++ b/core/src/test/java/google/registry/flows/host/HostUpdateFlowTest.java
@@ -79,15 +79,22 @@ import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.DomainTransferData;
 import google.registry.model.transfer.TransferStatus;
 import google.registry.testing.DualDatabaseTest;
+import google.registry.testing.ReplayExtension;
 import google.registry.testing.TaskQueueHelper.TaskMatcher;
 import google.registry.testing.TestOfyAndSql;
 import javax.annotation.Nullable;
 import org.joda.time.DateTime;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link HostUpdateFlow}. */
 @DualDatabaseTest
 class HostUpdateFlowTest extends ResourceFlowTestCase<HostUpdateFlow, HostResource> {
 
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   private void setEppHostUpdateInput(
       String oldHostName, String newHostName, String ipOrStatusToAdd, String ipOrStatusToRem) {
     setEppInput(
@@ -712,6 +719,7 @@ class HostUpdateFlowTest extends ResourceFlowTestCase<HostUpdateFlow, HostResour
             .build());
     clock.advanceOneMilli();
     HostResource renamedHost = doSuccessfulTest();
+    clock.advanceOneMilli();
     persistResource(domain.asBuilder().setLastTransferTime(clock.nowUtc().minusDays(1)).build());
     // The last transfer time should be what was on the superordinate domain at the time of the host
     // update, not what it is later changed to.
@@ -721,7 +729,9 @@ class HostUpdateFlowTest extends ResourceFlowTestCase<HostUpdateFlow, HostResour
         .and()
         .hasLastTransferTime(lastTransferTime)
         .and()
-        .hasLastSuperordinateChange(clock.nowUtc());
+        // Need to add two milliseconds to account for the increment of "persist resource" and the
+        // artificial increment introduced after the flow itself.
+        .hasLastSuperordinateChange(clock.nowUtc().minusMillis(2));
   }
 
   @TestOfyAndSql
diff --git a/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java b/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java
index 91f36c0cd..5a6e1f399 100644
--- a/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java
+++ b/core/src/test/java/google/registry/flows/poll/PollAckFlowTest.java
@@ -32,13 +32,20 @@ import google.registry.flows.poll.PollAckFlow.NotAuthorizedToAckMessageException
 import google.registry.model.contact.ContactResource;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.poll.PollMessage;
+import google.registry.testing.ReplayExtension;
 import org.joda.time.DateTime;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link PollAckFlow}. */
 class PollAckFlowTest extends FlowTestCase<PollAckFlow> {
 
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   /** This is the message id being sent in the ACK request. */
   private static final long MESSAGE_ID = 3;
 
diff --git a/core/src/test/java/google/registry/flows/poll/PollRequestFlowTest.java b/core/src/test/java/google/registry/flows/poll/PollRequestFlowTest.java
index 2e9a5b8e6..cc9fad844 100644
--- a/core/src/test/java/google/registry/flows/poll/PollRequestFlowTest.java
+++ b/core/src/test/java/google/registry/flows/poll/PollRequestFlowTest.java
@@ -19,6 +19,7 @@ import static google.registry.testing.DatabaseHelper.createTld;
 import static google.registry.testing.DatabaseHelper.newDomainBase;
 import static google.registry.testing.DatabaseHelper.persistActiveContact;
 import static google.registry.testing.DatabaseHelper.persistActiveHost;
+import static google.registry.testing.DatabaseHelper.persistNewRegistrar;
 import static google.registry.testing.DatabaseHelper.persistResource;
 import static google.registry.testing.EppExceptionSubject.assertAboutEppExceptions;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -37,13 +38,24 @@ import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.TransferResponse.ContactTransferResponse;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
 import google.registry.model.transfer.TransferStatus;
-import org.joda.time.DateTime;
+import google.registry.testing.ReplayExtension;
+import google.registry.testing.SetClockExtension;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
 
 /** Unit tests for {@link PollRequestFlow}. */
 class PollRequestFlowTest extends FlowTestCase<PollRequestFlow> {
 
+  @Order(value = Order.DEFAULT - 3)
+  @RegisterExtension
+  final SetClockExtension setClockExtension = new SetClockExtension(clock, "2011-01-02T01:01:01Z");
+
+  @Order(value = Order.DEFAULT - 2)
+  @RegisterExtension
+  final ReplayExtension replayExtension = ReplayExtension.createWithCompare(clock);
+
   private DomainBase domain;
   private ContactResource contact;
   private HostResource host;
@@ -52,8 +64,8 @@ class PollRequestFlowTest extends FlowTestCase<PollRequestFlow> {
   void setUp() {
     setEppInput("poll.xml");
     setClientIdForFlow("NewRegistrar");
-    clock.setTo(DateTime.parse("2011-01-02T01:01:01Z"));
     createTld("example");
+    persistNewRegistrar("BadRegistrar");
     contact = persistActiveContact("jd1234");
     domain = persistResource(newDomainBase("test.example", contact));
     host = persistActiveHost("ns1.test.example");
@@ -97,7 +109,6 @@ class PollRequestFlowTest extends FlowTestCase<PollRequestFlow> {
 
   @Test
   void testSuccess_contactTransferPending() throws Exception {
-    clock.setTo(DateTime.parse("2000-06-13T22:00:00.0Z"));
     setClientIdForFlow("TheRegistrar");
     persistResource(
         new PollMessage.OneTime.Builder()
@@ -157,7 +168,7 @@ class PollRequestFlowTest extends FlowTestCase<PollRequestFlow> {
   void testSuccess_wrongRegistrar() throws Exception {
     persistResource(
         new PollMessage.OneTime.Builder()
-            .setClientId("different client id")
+            .setClientId("BadRegistrar")
             .setEventTime(clock.nowUtc().minusDays(1))
             .setMsg("Poll message")
             .setParent(createHistoryEntryForEppResource(domain))
@@ -229,6 +240,7 @@ class PollRequestFlowTest extends FlowTestCase<PollRequestFlow> {
             .setParent(historyEntry)
             .setEventTime(clock.nowUtc().minusDays(1))
             .build());
+    clock.advanceOneMilli();
     assertTransactionalFlow(false);
     runFlowAssertResponse(loadFile("poll_response_host_delete.xml"));
   }
diff --git a/core/src/test/java/google/registry/testing/DatabaseHelper.java b/core/src/test/java/google/registry/testing/DatabaseHelper.java
index feed9ca31..2102484ef 100644
--- a/core/src/test/java/google/registry/testing/DatabaseHelper.java
+++ b/core/src/test/java/google/registry/testing/DatabaseHelper.java
@@ -1168,7 +1168,12 @@ public class DatabaseHelper {
 
   public static <T extends EppResource> HistoryEntry createHistoryEntryForEppResource(
       T parentResource) {
-    return persistResource(new HistoryEntry.Builder().setParent(parentResource).build());
+    return persistResource(
+        new HistoryEntry.Builder()
+            .setType(getHistoryEntryType(parentResource))
+            .setModificationTime(DateTime.now(DateTimeZone.UTC))
+            .setParent(parentResource)
+            .build());
   }
 
   /** Persists a single Objectify resource, without adjusting foreign resources or keys. */
diff --git a/core/src/test/java/google/registry/testing/SetClockExtension.java b/core/src/test/java/google/registry/testing/SetClockExtension.java
new file mode 100644
index 000000000..df443cefa
--- /dev/null
+++ b/core/src/test/java/google/registry/testing/SetClockExtension.java
@@ -0,0 +1,47 @@
+// Copyright 2021 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.testing;
+
+import org.joda.time.DateTime;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+/**
+ * Extension used for tests that a) set the clock to a specific time and b) make use of
+ * ReplayExtension or any other test feature that requires writing to a commit log from test
+ * utilities that aren't controlled by the ultimate test class (e.g. AppEngineExtension).
+ */
+public class SetClockExtension implements BeforeEachCallback {
+
+  private FakeClock clock;
+  private DateTime dateTime;
+
+  /** Construct from a DateTime, that being the time to set the clock to. */
+  public SetClockExtension(FakeClock clock, DateTime dateTime) {
+    this.clock = clock;
+    this.dateTime = dateTime;
+  }
+
+  /** Construct from a dateTime (the time to set the clock to) represented as a string. */
+  public SetClockExtension(FakeClock clock, String dateTime) {
+    this.clock = clock;
+    this.dateTime = DateTime.parse(dateTime);
+  }
+
+  @Override
+  public void beforeEach(ExtensionContext context) {
+    clock.setTo(dateTime);
+  }
+}
diff --git a/core/src/test/resources/google/registry/flows/poll/poll_response_contact_transfer.xml b/core/src/test/resources/google/registry/flows/poll/poll_response_contact_transfer.xml
index 7dfdb112f..54b0c5f4a 100644
--- a/core/src/test/resources/google/registry/flows/poll/poll_response_contact_transfer.xml
+++ b/core/src/test/resources/google/registry/flows/poll/poll_response_contact_transfer.xml
@@ -3,8 +3,8 @@
     <result code="1301">
       <msg>Command completed successfully; ack to dequeue</msg>
     </result>
-    <msgQ count="1" id="2-2-ROID-5-3-2000">
-      <qDate>2000-06-08T22:00:00Z</qDate>
+    <msgQ count="1" id="2-2-ROID-5-3-2010">
+      <qDate>2010-12-28T01:01:01Z</qDate>
       <msg>Transfer requested.</msg>
     </msgQ>
     <resData>
@@ -12,9 +12,9 @@
         <contact:id>sh8013</contact:id>
         <contact:trStatus>pending</contact:trStatus>
         <contact:reID>TheRegistrar</contact:reID>
-        <contact:reDate>2000-06-08T22:00:00.0Z</contact:reDate>
+        <contact:reDate>2010-12-28T01:01:01Z</contact:reDate>
         <contact:acID>NewRegistrar</contact:acID>
-        <contact:acDate>2000-06-13T22:00:00.0Z</contact:acDate>
+        <contact:acDate>2011-01-02T01:01:01Z</contact:acDate>
       </contact:trnData>
     </resData>
     <trID>
diff --git a/db/src/main/resources/sql/er_diagram/brief_er_diagram.html b/db/src/main/resources/sql/er_diagram/brief_er_diagram.html
index 62b70ce3b..590d5b0cb 100644
--- a/db/src/main/resources/sql/er_diagram/brief_er_diagram.html
+++ b/db/src/main/resources/sql/er_diagram/brief_er_diagram.html
@@ -261,11 +261,11 @@ td.section {
     </tr> 
     <tr> 
      <td class="property_name">generated on</td> 
-     <td class="property_value">2021-03-18 19:08:16.381352</td> 
+     <td class="property_value">2021-03-19 12:31:33.396532</td> 
     </tr> 
     <tr>
      <td class="property_name">last flyway file</td>
-     <td id="lastFlywayFile" class="property_value">V88__transfer_billing_cancellation_history_id.sql</td>
+     <td id="lastFlywayFile" class="property_value">V89__host_history_host_deferred.sql</td>
     </tr>
    </tbody>
   </table> 
@@ -284,7 +284,7 @@ td.section {
      generated on
     </text> 
     <text text-anchor="start" x="4027.94" y="-10.8" font-family="Helvetica,sans-Serif" font-size="14.00">
-     2021-03-18 19:08:16.381352
+     2021-03-19 12:31:33.396532
     </text> 
     <polygon fill="none" stroke="#888888" points="3940.44,-4 3940.44,-44 4205.44,-44 4205.44,-4 3940.44,-4" /> <!-- allocationtoken_a08ccbef --> 
     <g id="node1" class="node"> 
@@ -2484,8 +2484,8 @@ td.section {
      <polyline fill="none" stroke="black" points="191.5,-646.68 195.4,-643.55 " /> 
      <polygon fill="black" stroke="black" points="199.31,-646.82 193.05,-639.02 194.61,-637.77 200.87,-645.57 199.31,-646.82" /> 
      <polyline fill="none" stroke="black" points="195.4,-643.55 199.3,-640.42 " /> 
-     <text text-anchor="start" x="1178.5" y="-280.48" font-family="Helvetica,sans-Serif" font-size="14.00">
-      fk3d09knnmxrt6iniwnp8j2ykga
+     <text text-anchor="start" x="1203" y="-280.48" font-family="Helvetica,sans-Serif" font-size="14.00">
+      fk_history_registrar_id
      </text> 
     </g> <!-- kmssecret_f3b28857 --> 
     <g id="node22" class="node"> 
@@ -5357,7 +5357,7 @@ td.section {
      <td colspan="3"></td> 
     </tr> 
     <tr> 
-     <td colspan="2" class="name">fk3d09knnmxrt6iniwnp8j2ykga</td> 
+     <td colspan="2" class="name">fk_history_registrar_id</td> 
      <td class="description right">[foreign key, with no action]</td> 
     </tr> 
     <tr> 
@@ -6110,7 +6110,7 @@ td.section {
      <td colspan="3"></td> 
     </tr> 
     <tr> 
-     <td colspan="2" class="name">fk3d09knnmxrt6iniwnp8j2ykga</td> 
+     <td colspan="2" class="name">fk_history_registrar_id</td> 
      <td class="description right">[foreign key, with no action]</td> 
     </tr> 
     <tr> 
diff --git a/db/src/main/resources/sql/er_diagram/full_er_diagram.html b/db/src/main/resources/sql/er_diagram/full_er_diagram.html
index 434149697..54c3b23a5 100644
--- a/db/src/main/resources/sql/er_diagram/full_er_diagram.html
+++ b/db/src/main/resources/sql/er_diagram/full_er_diagram.html
@@ -261,11 +261,11 @@ td.section {
     </tr> 
     <tr> 
      <td class="property_name">generated on</td> 
-     <td class="property_value">2021-03-18 19:08:14.574191</td> 
+     <td class="property_value">2021-03-19 12:31:31.233378</td> 
     </tr> 
     <tr>
      <td class="property_name">last flyway file</td>
-     <td id="lastFlywayFile" class="property_value">V88__transfer_billing_cancellation_history_id.sql</td>
+     <td id="lastFlywayFile" class="property_value">V89__host_history_host_deferred.sql</td>
     </tr>
    </tbody>
   </table> 
@@ -284,7 +284,7 @@ td.section {
      generated on
     </text> 
     <text text-anchor="start" x="4626.68" y="-10.8" font-family="Helvetica,sans-Serif" font-size="14.00">
-     2021-03-18 19:08:14.574191
+     2021-03-19 12:31:31.233378
     </text> 
     <polygon fill="none" stroke="#888888" points="4539.18,-4 4539.18,-44 4804.18,-44 4804.18,-4 4539.18,-4" /> <!-- allocationtoken_a08ccbef --> 
     <g id="node1" class="node"> 
@@ -5580,8 +5580,8 @@ td.section {
      <polyline fill="none" stroke="black" points="298,-1144.89 302.29,-1142.32 " /> 
      <polygon fill="black" stroke="black" points="305.72,-1146.1 300.58,-1137.52 302.3,-1136.49 307.43,-1145.08 305.72,-1146.1" /> 
      <polyline fill="none" stroke="black" points="302.29,-1142.32 306.58,-1139.76 " /> 
-     <text text-anchor="start" x="1422" y="-485.69" font-family="Helvetica,sans-Serif" font-size="14.00">
-      fk3d09knnmxrt6iniwnp8j2ykga
+     <text text-anchor="start" x="1446.5" y="-485.69" font-family="Helvetica,sans-Serif" font-size="14.00">
+      fk_history_registrar_id
      </text> 
     </g> <!-- kmssecret_f3b28857 --> 
     <g id="node22" class="node"> 
@@ -11079,7 +11079,7 @@ td.section {
      <td colspan="3"></td> 
     </tr> 
     <tr> 
-     <td colspan="2" class="name">fk3d09knnmxrt6iniwnp8j2ykga</td> 
+     <td colspan="2" class="name">fk_history_registrar_id</td> 
      <td class="description right">[foreign key, with no action]</td> 
     </tr> 
     <tr> 
@@ -12436,7 +12436,7 @@ td.section {
      <td colspan="3"></td> 
     </tr> 
     <tr> 
-     <td colspan="2" class="name">fk3d09knnmxrt6iniwnp8j2ykga</td> 
+     <td colspan="2" class="name">fk_history_registrar_id</td> 
      <td class="description right">[foreign key, with no action]</td> 
     </tr> 
     <tr> 
diff --git a/db/src/main/resources/sql/flyway.txt b/db/src/main/resources/sql/flyway.txt
index c1f4cc3f1..fdbf14e20 100644
--- a/db/src/main/resources/sql/flyway.txt
+++ b/db/src/main/resources/sql/flyway.txt
@@ -86,3 +86,4 @@ V85__add_required_columns_in_transfer_data.sql
 V86__third_poll_message.sql
 V87__fix_super_domain_fk.sql
 V88__transfer_billing_cancellation_history_id.sql
+V89__host_history_host_deferred.sql
diff --git a/db/src/main/resources/sql/flyway/V89__host_history_host_deferred.sql b/db/src/main/resources/sql/flyway/V89__host_history_host_deferred.sql
new file mode 100644
index 000000000..a9b990a17
--- /dev/null
+++ b/db/src/main/resources/sql/flyway/V89__host_history_host_deferred.sql
@@ -0,0 +1,25 @@
+-- Copyright 2021 The Nomulus Authors. All Rights Reserved.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+ALTER TABLE "HostHistory" DROP CONSTRAINT fk3d09knnmxrt6iniwnp8j2ykga;
+ALTER TABLE "HostHistory" DROP CONSTRAINT fk_hosthistory_host;
+ALTER TABLE "HostHistory" ADD CONSTRAINT fk_history_registrar_id
+    FOREIGN KEY (history_registrar_id)
+    REFERENCES "Registrar"(registrar_id)
+    DEFERRABLE INITIALLY DEFERRED;
+ALTER TABLE "HostHistory" ADD CONSTRAINT fk_hosthistory_host
+    FOREIGN KEY (host_repo_id)
+    REFERENCES "Host"(repo_id)
+    DEFERRABLE INITIALLY DEFERRED;
+
diff --git a/db/src/main/resources/sql/schema/nomulus.golden.sql b/db/src/main/resources/sql/schema/nomulus.golden.sql
index 10a3274ae..6c2baad19 100644
--- a/db/src/main/resources/sql/schema/nomulus.golden.sql
+++ b/db/src/main/resources/sql/schema/nomulus.golden.sql
@@ -1867,14 +1867,6 @@ ALTER TABLE ONLY public."Domain"
     ADD CONSTRAINT fk2u3srsfbei272093m3b3xwj23 FOREIGN KEY (current_sponsor_registrar_id) REFERENCES public."Registrar"(registrar_id);
 
 
---
--- Name: HostHistory fk3d09knnmxrt6iniwnp8j2ykga; Type: FK CONSTRAINT; Schema: public; Owner: -
---
-
-ALTER TABLE ONLY public."HostHistory"
-    ADD CONSTRAINT fk3d09knnmxrt6iniwnp8j2ykga FOREIGN KEY (history_registrar_id) REFERENCES public."Registrar"(registrar_id);
-
-
 --
 -- Name: SignedMarkRevocationEntry fk5ivlhvs3121yx2li5tqh54u4; Type: FK CONSTRAINT; Schema: public; Owner: -
 --
@@ -2171,6 +2163,14 @@ ALTER TABLE ONLY public."GracePeriod"
     ADD CONSTRAINT fk_grace_period_registrar_id FOREIGN KEY (registrar_id) REFERENCES public."Registrar"(registrar_id);
 
 
+--
+-- Name: HostHistory fk_history_registrar_id; Type: FK CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public."HostHistory"
+    ADD CONSTRAINT fk_history_registrar_id FOREIGN KEY (history_registrar_id) REFERENCES public."Registrar"(registrar_id) DEFERRABLE INITIALLY DEFERRED;
+
+
 --
 -- Name: Host fk_host_creation_registrar_id; Type: FK CONSTRAINT; Schema: public; Owner: -
 --
@@ -2208,7 +2208,7 @@ ALTER TABLE ONLY public."Host"
 --
 
 ALTER TABLE ONLY public."HostHistory"
-    ADD CONSTRAINT fk_hosthistory_host FOREIGN KEY (host_repo_id) REFERENCES public."Host"(repo_id);
+    ADD CONSTRAINT fk_hosthistory_host FOREIGN KEY (host_repo_id) REFERENCES public."Host"(repo_id) DEFERRABLE INITIALLY DEFERRED;
 
 
 --