diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index 2c9d5de6d9..7acde4c7c9 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -121,7 +121,8 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
  */
 static void
 create_logical_replication_slot(char *name, char *plugin,
-								bool temporary, XLogRecPtr restart_lsn)
+								bool temporary, XLogRecPtr restart_lsn,
+								bool build_snapshot)
 {
 	LogicalDecodingContext *ctx = NULL;
 
@@ -148,7 +149,8 @@ create_logical_replication_slot(char *name, char *plugin,
 									NULL);
 
 	/* build initial snapshot, might take a while */
-	DecodingContextFindStartpoint(ctx);
+	if (build_snapshot)
+		DecodingContextFindStartpoint(ctx);
 
 	/* don't need the decoding context anymore */
 	FreeDecodingContext(ctx);
@@ -179,7 +181,8 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
 	create_logical_replication_slot(NameStr(*name),
 									NameStr(*plugin),
 									temporary,
-									InvalidXLogRecPtr);
+									InvalidXLogRecPtr,
+									true);
 
 	values[0] = NameGetDatum(&MyReplicationSlot->data.name);
 	values[1] = LSNGetDatum(MyReplicationSlot->data.confirmed_flush);
@@ -596,6 +599,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 	Name		dst_name = PG_GETARG_NAME(1);
 	ReplicationSlot *src = NULL;
 	XLogRecPtr	src_restart_lsn;
+	XLogRecPtr	src_confirmed_flush;
 	bool		src_islogical;
 	bool		temporary;
 	char	   *plugin;
@@ -637,6 +641,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 			SpinLockAcquire(&s->mutex);
 			src_islogical = SlotIsLogical(s);
 			src_restart_lsn = s->data.restart_lsn;
+			src_confirmed_flush = s->data.confirmed_flush;
 			temporary = s->data.persistency == RS_TEMPORARY;
 			plugin = logical_slot ? pstrdup(NameStr(s->data.plugin)) : NULL;
 			SpinLockRelease(&s->mutex);
@@ -672,6 +677,13 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 				 errmsg("cannot copy a replication slot that doesn't reserve WAL")));
 	}
 
+	/* The source slot needs to have a consistent snapshot */
+	if (src_islogical && XLogRecPtrIsInvalid(src_confirmed_flush))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot copy a logical replication slot that doesn't have confirmed flush WAL location (LSN)"),
+				 errhint("Retry once the source replication slot found consistent point")));
+
 	/* Overwrite params from optional arguments */
 	if (PG_NARGS() >= 3)
 		temporary = PG_GETARG_BOOL(2);
@@ -683,10 +695,19 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 
 	/* Create new slot and acquire it */
 	if (logical_slot)
+	{
+		/*
+		 * WAL required for building snapshot could be removed as we don't reserve
+		 * WAL yet. So we create a new logical replication slot without building
+		 * an initial snapshot.  A resonable start point for decoding will be set by
+		 * copying from the source slot.
+		 */
 		create_logical_replication_slot(NameStr(*dst_name),
 										plugin,
 										temporary,
-										src_restart_lsn);
+										src_restart_lsn,
+										false);
+	}
 	else
 		create_physical_replication_slot(NameStr(*dst_name),
 										 true,
@@ -703,6 +724,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 		TransactionId copy_xmin;
 		TransactionId copy_catalog_xmin;
 		XLogRecPtr	copy_restart_lsn;
+		XLogRecPtr	copy_confirmed_flush;
 		bool		copy_islogical;
 		char	   *copy_name;
 
@@ -714,6 +736,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 		copy_xmin = src->data.xmin;
 		copy_catalog_xmin = src->data.catalog_xmin;
 		copy_restart_lsn = src->data.restart_lsn;
+		copy_confirmed_flush = src->data.confirmed_flush;
 
 		/* for existence check */
 		copy_name = pstrdup(NameStr(src->data.name));
@@ -746,6 +769,7 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 		MyReplicationSlot->data.xmin = copy_xmin;
 		MyReplicationSlot->data.catalog_xmin = copy_catalog_xmin;
 		MyReplicationSlot->data.restart_lsn = copy_restart_lsn;
+		MyReplicationSlot->data.confirmed_flush = copy_confirmed_flush;
 		SpinLockRelease(&MyReplicationSlot->mutex);
 
 		ReplicationSlotMarkDirty();