diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index d9a2ce5e40d..02e02e3fa8c 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -5410,6 +5410,7 @@ StartupXLOG(void)
 			 * during recovery and need not be started yet.
 			 */
 			StartupSUBTRANS(oldestActiveXID);
+			SetRecoverySubtransInitialized();
 
 			/*
 			 * If we're beginning at a shutdown checkpoint, we know that
@@ -7425,10 +7426,10 @@ CreateRestartPoint(int flags)
 	 * Truncate pg_subtrans if possible.  We can throw away all data before
 	 * the oldest XMIN of any running transaction.  No future transaction will
 	 * attempt to reference any pg_subtrans entry older than that (see Asserts
-	 * in subtrans.c).  When hot standby is disabled, though, we mustn't do
-	 * this because StartupSUBTRANS hasn't been called yet.
+	 * in subtrans.c).  During recovery, don't truncate pg_subtrans until hot
+	 * standby initialization has started it.
 	 */
-	if (EnableHotStandby)
+	if (RecoverySubtransInitialized())
 		TruncateSUBTRANS(GetOldestTransactionIdConsideredRunning());
 
 	/* Real work is done; log and update stats. */
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 512abcc6ab7..0838d2c686e 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -315,6 +315,12 @@ typedef struct XLogRecoveryCtlData
 	 */
 	bool		SharedPromoteIsTriggered;
 
+	/*
+	 * SharedRecoverySubtransInitialized indicates whether hot standby
+	 * initialization has started pg_subtrans. Protected by info_lck.
+	 */
+	bool		SharedRecoverySubtransInitialized;
+
 	/*
 	 * recoveryWakeupLatch is used to wake up the startup process to continue
 	 * WAL replay, if it is waiting for WAL to arrive or promotion to be
@@ -4442,6 +4448,32 @@ CheckPromoteSignal(void)
 	return false;
 }
 
+/*
+ * Has hot standby initialization started pg_subtrans?
+ */
+bool
+RecoverySubtransInitialized(void)
+{
+	bool		result;
+
+	SpinLockAcquire(&XLogRecoveryCtl->info_lck);
+	result = XLogRecoveryCtl->SharedRecoverySubtransInitialized;
+	SpinLockRelease(&XLogRecoveryCtl->info_lck);
+
+	return result;
+}
+
+/*
+ * Remember that hot standby initialization has started pg_subtrans.
+ */
+void
+SetRecoverySubtransInitialized(void)
+{
+	SpinLockAcquire(&XLogRecoveryCtl->info_lck);
+	XLogRecoveryCtl->SharedRecoverySubtransInitialized = true;
+	SpinLockRelease(&XLogRecoveryCtl->info_lck);
+}
+
 /*
  * Wake up startup process to replay newly arrived WAL, or to notice that
  * failover has been requested.
diff --git a/src/include/access/xlogrecovery.h b/src/include/access/xlogrecovery.h
index 47c29350f5d..7737f9e2cf0 100644
--- a/src/include/access/xlogrecovery.h
+++ b/src/include/access/xlogrecovery.h
@@ -146,6 +146,8 @@ extern XLogRecPtr GetCurrentReplayRecPtr(TimeLineID *replayEndTLI);
 
 extern bool PromoteIsTriggered(void);
 extern bool CheckPromoteSignal(void);
+extern bool RecoverySubtransInitialized(void);
+extern void SetRecoverySubtransInitialized(void);
 extern void WakeupRecovery(void);
 
 extern void StartupRequestWalReceiverRestart(void);