diff --git a/app/src/main/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2.kt b/app/src/main/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2.kt
index c225aef341..94d77b420b 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2.kt
@@ -444,6 +444,7 @@ class IndividualSendJobV2 private constructor(parameters: Parameters, private va
           timestamp = timestamp,
           message = dataMessage,
           editMessage = editMessage,
+          expirationStartTimestamp = if ((dataMessage?.expireTimer ?: 0) > 0) System.currentTimeMillis() else null,
           unidentifiedStatus = listOf(
             SyncMessage.Sent.UnidentifiedDeliveryStatus(
               destinationServiceIdBinary = recipientServiceId.toByteString(),
diff --git a/app/src/test/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2Test.kt b/app/src/test/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2Test.kt
index 37c1b96843..3126e0eda5 100644
--- a/app/src/test/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2Test.kt
+++ b/app/src/test/java/org/thoughtcrime/securesms/jobs/IndividualSendJobV2Test.kt
@@ -11,6 +11,9 @@ import arrow.core.left
 import arrow.core.right
 import assertk.assertThat
 import assertk.assertions.isEqualTo
+import assertk.assertions.isGreaterThan
+import assertk.assertions.isNotNull
+import assertk.assertions.isNull
 import assertk.assertions.isTrue
 import io.mockk.coEvery
 import io.mockk.coVerify
@@ -427,6 +430,46 @@ class IndividualSendJobV2Test {
     }
   }
 
+  @Test
+  fun `Given multi-device and an expiring message, when send succeeds, then sync transcript carries expirationStartTimestamp`() {
+    every { signalStore.account.isMultiDevice } returns true
+    every { outgoingMessage.expiresIn } returns 60_000L
+    dataMessage = DataMessage(timestamp = sentTime, expireTimer = 60)
+    every { outgoingMessage.toDataMessage() } returns dataMessage.right()
+
+    val syncSlot = slot<EnvelopeContent>()
+    val primaryContent = EnvelopeContent.encrypted(Content(dataMessage = dataMessage), ContentHint.RESENDABLE, Optional.empty())
+    coEvery {
+      messageService.sendMessage(any(), any(), any(), any(), any(), any(), any(), any())
+    } returns MessageService.SendSuccess(envelopeContent = primaryContent, sentSealedSender = false, devices = listOf(1)).right()
+    coEvery {
+      messageService.sendSyncMessage(timestamp = any(), envelopeContent = capture(syncSlot), urgent = any(), onEncrypted = any())
+    } returns MessageService.SendSuccess(envelopeContent = primaryContent, sentSealedSender = false, devices = listOf(1)).right()
+
+    createAndRunJob()
+
+    val sent = syncSlot.captured.content.get().syncMessage!!.sent!!
+    assertThat(sent.expirationStartTimestamp).isNotNull().isGreaterThan(0L)
+  }
+
+  @Test
+  fun `Given multi-device and a non-expiring message, when send succeeds, then sync transcript omits expirationStartTimestamp`() {
+    every { signalStore.account.isMultiDevice } returns true
+
+    val syncSlot = slot<EnvelopeContent>()
+    coEvery {
+      messageService.sendSyncMessage(timestamp = any(), envelopeContent = capture(syncSlot), urgent = any(), onEncrypted = any())
+    } returns MessageService.SendSuccess(envelopeContent = EnvelopeContent.encrypted(Content(dataMessage = dataMessage), ContentHint.RESENDABLE, Optional.empty()), sentSealedSender = false, devices = listOf(1)).right()
+    coEvery {
+      messageService.sendMessage(any(), any(), any(), any(), any(), any(), any(), any())
+    } returns MessageService.SendSuccess(envelopeContent = EnvelopeContent.encrypted(Content(dataMessage = dataMessage), ContentHint.RESENDABLE, Optional.empty()), sentSealedSender = false, devices = listOf(1)).right()
+
+    createAndRunJob()
+
+    val sent = syncSlot.captured.content.get().syncMessage!!.sent!!
+    assertThat(sent.expirationStartTimestamp).isNull()
+  }
+
   @Test
   fun `Given an edit of an already-edited message, when run, then target the edited revision's dateSent`() {
     val editTargetMessageId = messageId + 1