diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 9a8a6bb119..5916697214 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -803,7 +803,7 @@ pg_prepared_xact(PG_FUNCTION_ARGS)
  *		specified by XID
  */
 static GlobalTransaction
-TwoPhaseGetGXact(TransactionId xid)
+TwoPhaseGetGXact(TransactionId xid, bool lock_held)
 {
 	GlobalTransaction result = NULL;
 	int			i;
@@ -811,6 +811,9 @@ TwoPhaseGetGXact(TransactionId xid)
 	static TransactionId cached_xid = InvalidTransactionId;
 	static GlobalTransaction cached_gxact = NULL;
 
+	Assert(!lock_held ||
+		   LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
+
 	/*
 	 * During a recovery, COMMIT PREPARED, or ABORT PREPARED, we'll be called
 	 * repeatedly for the same XID.  We can save work with a simple cache.
@@ -818,7 +821,8 @@ TwoPhaseGetGXact(TransactionId xid)
 	if (xid == cached_xid)
 		return cached_gxact;
 
-	LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+	if (!lock_held)
+		LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
 
 	for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
 	{
@@ -832,7 +836,8 @@ TwoPhaseGetGXact(TransactionId xid)
 		}
 	}
 
-	LWLockRelease(TwoPhaseStateLock);
+	if (!lock_held)
+		LWLockRelease(TwoPhaseStateLock);
 
 	if (result == NULL)			/* should not happen */
 		elog(ERROR, "failed to find GlobalTransaction for xid %u", xid);
@@ -854,7 +859,7 @@ TwoPhaseGetGXact(TransactionId xid)
 BackendId
 TwoPhaseGetDummyBackendId(TransactionId xid)
 {
-	GlobalTransaction gxact = TwoPhaseGetGXact(xid);
+	GlobalTransaction gxact = TwoPhaseGetGXact(xid, false);
 
 	return gxact->dummyBackendId;
 }
@@ -864,9 +869,9 @@ TwoPhaseGetDummyBackendId(TransactionId xid)
  *		Get the PGPROC that represents a prepared transaction specified by XID
  */
 PGPROC *
-TwoPhaseGetDummyProc(TransactionId xid)
+TwoPhaseGetDummyProc(TransactionId xid, bool lock_held)
 {
-	GlobalTransaction gxact = TwoPhaseGetGXact(xid);
+	GlobalTransaction gxact = TwoPhaseGetGXact(xid, lock_held);
 
 	return &ProcGlobal->allProcs[gxact->pgprocno];
 }
@@ -1560,6 +1565,16 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
 	if (hdr->initfileinval)
 		RelationCacheInitFilePostInvalidate();
 
+	/* Count the prepared xact as committed or aborted */
+	AtEOXact_PgStat(isCommit);
+
+	/*
+	 * Acquire the two-phase lock, we want to work on the two-phase
+	 * callbacks while holding it to avoid potential conflicts with
+	 * other transactions, until the shared memory state is cleared.
+	 */
+	LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
+
 	/* And now do the callbacks */
 	if (isCommit)
 		ProcessRecords(bufptr, xid, twophase_postcommit_callbacks);
@@ -1568,8 +1583,14 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
 
 	PredicateLockTwoPhaseFinish(xid, isCommit);
 
-	/* Count the prepared xact as committed or aborted */
-	AtEOXact_PgStat(isCommit);
+	/* Clear shared memory state */
+	RemoveGXact(gxact);
+
+	/*
+	 * Release the lock as all callbacks are called and shared memory
+	 * cleanup is done.
+	 */
+	LWLockRelease(TwoPhaseStateLock);
 
 	/*
 	 * And now we can clean up any files we may have left.
@@ -1577,9 +1598,6 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
 	if (gxact->ondisk)
 		RemoveTwoPhaseFile(xid, true);
 
-	LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
-	RemoveGXact(gxact);
-	LWLockRelease(TwoPhaseStateLock);
 	MyLockedGxact = NULL;
 
 	RESUME_INTERRUPTS();
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 3bb5ce350a..78fdbd6ff8 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -3243,7 +3243,7 @@ AtPrepare_Locks(void)
 void
 PostPrepare_Locks(TransactionId xid)
 {
-	PGPROC	   *newproc = TwoPhaseGetDummyProc(xid);
+	PGPROC	   *newproc = TwoPhaseGetDummyProc(xid, false);
 	HASH_SEQ_STATUS status;
 	LOCALLOCK  *locallock;
 	LOCK	   *lock;
@@ -4034,7 +4034,7 @@ lock_twophase_recover(TransactionId xid, uint16 info,
 					  void *recdata, uint32 len)
 {
 	TwoPhaseLockRecord *rec = (TwoPhaseLockRecord *) recdata;
-	PGPROC	   *proc = TwoPhaseGetDummyProc(xid);
+	PGPROC	   *proc = TwoPhaseGetDummyProc(xid, false);
 	LOCKTAG    *locktag;
 	LOCKMODE	lockmode;
 	LOCKMETHODID lockmethodid;
@@ -4247,7 +4247,7 @@ lock_twophase_postcommit(TransactionId xid, uint16 info,
 						 void *recdata, uint32 len)
 {
 	TwoPhaseLockRecord *rec = (TwoPhaseLockRecord *) recdata;
-	PGPROC	   *proc = TwoPhaseGetDummyProc(xid);
+	PGPROC	   *proc = TwoPhaseGetDummyProc(xid, true);
 	LOCKTAG    *locktag;
 	LOCKMETHODID lockmethodid;
 	LockMethod	lockMethodTable;
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index 6228b091d8..2dcd08e9fa 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -34,7 +34,7 @@ extern void TwoPhaseShmemInit(void);
 extern void AtAbort_Twophase(void);
 extern void PostPrepare_Twophase(void);
 
-extern PGPROC *TwoPhaseGetDummyProc(TransactionId xid);
+extern PGPROC *TwoPhaseGetDummyProc(TransactionId xid, bool lock_held);
 extern BackendId TwoPhaseGetDummyBackendId(TransactionId xid);
 
 extern GlobalTransaction MarkAsPreparing(TransactionId xid, const char *gid,