diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index bf2f4db..bdf1f65 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -793,13 +793,8 @@ ProcArrayApplyRecoveryInfo(RunningTransactions running)
 		}
 
 		/*
-		 * Sort the array so that we can add them safely into
-		 * KnownAssignedXids.
-		 */
-		qsort(xids, nxids, sizeof(TransactionId), xidComparator);
-
-		/*
-		 * Add the sorted snapshot into KnownAssignedXids
+		 * Add the sorted snapshot into KnownAssignedXids,
+		 * xids are already sorted by LogCurrentRunningXacts
 		 */
 		for (i = 0; i < nxids; i++)
 			KnownAssignedXidsAdd(xids[i], xids[i], true);
@@ -1898,7 +1893,8 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc)
  * GetRunningTransactionData -- returns information about running transactions.
  *
  * Similar to GetSnapshotData but returns more information. We include
- * all PGXACTs with an assigned TransactionId, even VACUUM processes.
+ * all PGXACTs with an assigned TransactionId, even VACUUM processes and
+ * dummy two-phase related entries created when preparing the transaction.
  *
  * We acquire XidGenLock and ProcArrayLock, but the caller is responsible for
  * releasing them. Acquiring XidGenLock ensures that no new XIDs enter the proc
diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c
index c9bb3e9..57b0e26 100644
--- a/src/backend/storage/ipc/standby.c
+++ b/src/backend/storage/ipc/standby.c
@@ -29,6 +29,7 @@
 #include "storage/procarray.h"
 #include "storage/sinvaladt.h"
 #include "storage/standby.h"
+#include "utils/builtins.h"
 #include "utils/hsearch.h"
 #include "utils/memutils.h"
 #include "utils/ps_status.h"
@@ -977,9 +978,20 @@ LogCurrentRunningXacts(RunningTransactions CurrRunningXacts)
 
 	/* array of TransactionIds */
 	if (xlrec.xcnt > 0)
-		XLogRegisterData((char *) CurrRunningXacts->xids,
-						 (xlrec.xcnt + xlrec.subxcnt) * sizeof(TransactionId));
+	{
+		int i, j, nxids = xlrec.xcnt + xlrec.subxcnt;
+		TransactionId* xids = CurrRunningXacts->xids;
+
+		/* Sort XIDs array and exclude duplicated XIDs caused by two-phase related entries */
+		qsort(xids, nxids, sizeof(TransactionId), xidComparator);
 
+		for (i=0, j=1; j < nxids; j++)
+			if (xids[i] != xids[j])
+				xids[++i] = xids[j];
+
+		nxids = i + 1;
+		XLogRegisterData((char *) xids, nxids * sizeof(TransactionId));
+	}
 	recptr = XLogInsert(RM_STANDBY_ID, XLOG_RUNNING_XACTS);
 
 	if (CurrRunningXacts->subxid_overflow)