diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index a00786d40c8..ffea4993177 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2215,25 +2215,6 @@ check_wal_segment_size(int *newval, void **extra, GucSource source)
 	return true;
 }
 
-/*
- * GUC check_hook for max_slot_wal_keep_size
- *
- * We don't allow the value of max_slot_wal_keep_size other than -1 during the
- * binary upgrade. See start_postmaster() in pg_upgrade for more details.
- */
-bool
-check_max_slot_wal_keep_size(int *newval, void **extra, GucSource source)
-{
-	if (IsBinaryUpgrade && *newval != -1)
-	{
-		GUC_check_errdetail("\"%s\" must be set to -1 during binary upgrade mode.",
-							"max_slot_wal_keep_size");
-		return false;
-	}
-
-	return true;
-}
-
 /*
  * At a checkpoint, how many WAL segments to recycle as preallocated future
  * XLOG segments? Returns the highest segment that should be preallocated.
@@ -7992,17 +7973,19 @@ KeepLogSeg(XLogRecPtr recptr, XLogRecPtr slotsMinReqLSN, XLogSegNo *logSegNo)
 	XLByteToSeg(recptr, currSegNo, wal_segment_size);
 	segno = currSegNo;
 
-	/*
-	 * Calculate how many segments are kept by slots first, adjusting for
-	 * max_slot_wal_keep_size.
-	 */
+	/* Calculate how many segments are kept by slots. */
 	keep = slotsMinReqLSN;
 	if (keep != InvalidXLogRecPtr && keep < recptr)
 	{
 		XLByteToSeg(keep, segno, wal_segment_size);
 
-		/* Cap by max_slot_wal_keep_size ... */
-		if (max_slot_wal_keep_size_mb >= 0)
+		/*
+		 * Account for max_slot_wal_keep_size to avoid keeping more than
+		 * configured.  However, don't do that during a binary upgrade: if
+		 * slots were to be invalidated because of this, it would not be
+		 * possible to preserve logical ones during the upgrade.
+		 */
+		if (max_slot_wal_keep_size_mb >= 0 && !IsBinaryUpgrade)
 		{
 			uint64		slot_keep_segs;
 
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index a1d4768623f..a234e2ca9c1 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -1671,14 +1671,6 @@ InvalidatePossiblyObsoleteSlot(ReplicationSlotInvalidationCause cause,
 
 		SpinLockRelease(&s->mutex);
 
-		/*
-		 * The logical replication slots shouldn't be invalidated as GUC
-		 * max_slot_wal_keep_size is set to -1 during the binary upgrade. See
-		 * check_old_cluster_for_valid_slots() where we ensure that no
-		 * invalidated before the upgrade.
-		 */
-		Assert(!(*invalidated && SlotIsLogical(s) && IsBinaryUpgrade));
-
 		if (active_pid != 0)
 		{
 			/*
@@ -1805,6 +1797,10 @@ restart:
 		if (!s->in_use)
 			continue;
 
+		/* Prevent invalidation of logical slots during binary upgrade. */
+		if (SlotIsLogical(s) && IsBinaryUpgrade)
+			continue;
+
 		if (InvalidatePossiblyObsoleteSlot(cause, s, oldestLSN, dboid,
 										   snapshotConflictHorizon,
 										   &invalidated))
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index c42fccf3fe7..a997dcb7dbc 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -2953,7 +2953,7 @@ struct config_int ConfigureNamesInt[] =
 		},
 		&max_slot_wal_keep_size_mb,
 		-1, -1, MAX_KILOBYTES,
-		check_max_slot_wal_keep_size, NULL, NULL
+		NULL, NULL, NULL
 	},
 
 	{
diff --git a/src/bin/pg_upgrade/server.c b/src/bin/pg_upgrade/server.c
index 91bcb4dbc7e..b223d5afddf 100644
--- a/src/bin/pg_upgrade/server.c
+++ b/src/bin/pg_upgrade/server.c
@@ -241,17 +241,6 @@ start_postmaster(ClusterInfo *cluster, bool report_and_exit_on_error)
 	if (cluster == &new_cluster)
 		appendPQExpBufferStr(&pgoptions, " -c synchronous_commit=off -c fsync=off -c full_page_writes=off");
 
-	/*
-	 * Use max_slot_wal_keep_size as -1 to prevent the WAL removal by the
-	 * checkpointer process.  If WALs required by logical replication slots
-	 * are removed, the slots are unusable.  This setting prevents the
-	 * invalidation of slots during the upgrade. We set this option when
-	 * cluster is PG17 or later because logical replication slots can only be
-	 * migrated since then. Besides, max_slot_wal_keep_size is added in PG13.
-	 */
-	if (GET_MAJOR_VERSION(cluster->major_version) >= 1700)
-		appendPQExpBufferStr(&pgoptions, " -c max_slot_wal_keep_size=-1");
-
 	/*
 	 * Use -b to disable autovacuum and logical replication launcher
 	 * (effective in PG17 or later for the latter).
diff --git a/src/include/utils/guc_hooks.h b/src/include/utils/guc_hooks.h
index 8fd91af3887..1babff78bf3 100644
--- a/src/include/utils/guc_hooks.h
+++ b/src/include/utils/guc_hooks.h
@@ -86,8 +86,6 @@ extern bool check_maintenance_io_concurrency(int *newval, void **extra,
 extern void assign_maintenance_io_concurrency(int newval, void *extra);
 extern bool check_max_connections(int *newval, void **extra, GucSource source);
 extern bool check_max_wal_senders(int *newval, void **extra, GucSource source);
-extern bool check_max_slot_wal_keep_size(int *newval, void **extra,
-										 GucSource source);
 extern void assign_max_wal_size(int newval, void *extra);
 extern bool check_max_worker_processes(int *newval, void **extra,
 									   GucSource source);