diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 3b6c636077..f86c05e8e0 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -2250,6 +2250,7 @@ static void
 InitWalSenderSlot(void)
 {
 	int			i;
+	bool		reject = false;
 
 	/*
 	 * WalSndCtl should be set up already (we inherit this by fork() or
@@ -2258,41 +2259,63 @@ InitWalSenderSlot(void)
 	Assert(WalSndCtl != NULL);
 	Assert(MyWalSnd == NULL);
 
+	/* limit the maximum number of non-reserved slots to use */
+	if (MyProc->procgloballist == &ProcGlobal->freeProcs)
+	{
+		int	max_normal_slots
+			= max_wal_senders - replication_reserved_connections;
+
+		if (max_normal_slots <= 0)
+		{
+			/* we mustn't use a normal slot */
+			reject = true;
+		}
+		else if (pg_atomic_add_fetch_u32(&WalSndCtl->n_using_normal_slots, 1)
+			> max_normal_slots)
+		{
+			pg_atomic_sub_fetch_u32(&WalSndCtl->n_using_normal_slots, 1);
+			reject = true;
+		}
+	}
+
 	/*
 	 * Find a free walsender slot and reserve it. If this fails, we must be
 	 * out of WalSnd structures.
 	 */
-	for (i = 0; i < max_wal_senders; i++)
+	if (!reject)
 	{
-		WalSnd	   *walsnd = &WalSndCtl->walsnds[i];
-
-		SpinLockAcquire(&walsnd->mutex);
-
-		if (walsnd->pid != 0)
+		for (i = 0; i < max_wal_senders; i++)
 		{
-			SpinLockRelease(&walsnd->mutex);
-			continue;
-		}
-		else
-		{
-			/*
-			 * Found a free slot. Reserve it for us.
-			 */
-			walsnd->pid = MyProcPid;
-			walsnd->sentPtr = InvalidXLogRecPtr;
-			walsnd->write = InvalidXLogRecPtr;
-			walsnd->flush = InvalidXLogRecPtr;
-			walsnd->apply = InvalidXLogRecPtr;
-			walsnd->writeLag = -1;
-			walsnd->flushLag = -1;
-			walsnd->applyLag = -1;
-			walsnd->state = WALSNDSTATE_STARTUP;
-			walsnd->latch = &MyProc->procLatch;
-			SpinLockRelease(&walsnd->mutex);
-			/* don't need the lock anymore */
-			MyWalSnd = (WalSnd *) walsnd;
+			WalSnd	   *walsnd = &WalSndCtl->walsnds[i];
 
-			break;
+			SpinLockAcquire(&walsnd->mutex);
+
+			if (walsnd->pid != 0)
+			{
+				SpinLockRelease(&walsnd->mutex);
+				continue;
+			}
+			else
+			{
+				/*
+				 * Found a free slot. Reserve it for us.
+				 */
+				walsnd->pid = MyProcPid;
+				walsnd->sentPtr = InvalidXLogRecPtr;
+				walsnd->write = InvalidXLogRecPtr;
+				walsnd->flush = InvalidXLogRecPtr;
+				walsnd->apply = InvalidXLogRecPtr;
+				walsnd->writeLag = -1;
+				walsnd->flushLag = -1;
+				walsnd->applyLag = -1;
+				walsnd->state = WALSNDSTATE_STARTUP;
+				walsnd->latch = &MyProc->procLatch;
+				SpinLockRelease(&walsnd->mutex);
+				/* don't need the lock anymore */
+				MyWalSnd = (WalSnd *) walsnd;
+
+				break;
+			}
 		}
 	}
 	if (MyWalSnd == NULL)
@@ -2322,6 +2345,10 @@ WalSndKill(int code, Datum arg)
 	/* Mark WalSnd struct as no longer being in use. */
 	walsnd->pid = 0;
 	SpinLockRelease(&walsnd->mutex);
+
+	/* decrement usage count of normal connection slots if needed */
+	if (MyProc->procgloballist == &ProcGlobal->freeProcs)
+		pg_atomic_sub_fetch_u32(&WalSndCtl->n_using_normal_slots, 1);
 }
 
 /*
@@ -3047,6 +3074,9 @@ WalSndShmemInit(void)
 
 			SpinLockInit(&walsnd->mutex);
 		}
+
+		/* set the number of non-reserved slots walsenders can use */
+		pg_atomic_init_u32(&WalSndCtl->n_using_normal_slots, 0);
 	}
 }
 
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 2d04a8204a..c461cf2f12 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -333,8 +333,7 @@ InitProcess(void)
 	* Try to use ProcGlobal->freeProcs as a fallback when
 	* all reserved walsender slots are already busy.
 	*/
-	if (am_walsender && replication_reserved_connections < max_wal_senders
-			&& *procgloballist == NULL)
+	if (am_walsender && *procgloballist == NULL)
 		procgloballist = &ProcGlobal->freeProcs;
 
 	MyProc = *procgloballist;
diff --git a/src/include/replication/walsender_private.h b/src/include/replication/walsender_private.h
index 4b90477936..bc84c287a4 100644
--- a/src/include/replication/walsender_private.h
+++ b/src/include/replication/walsender_private.h
@@ -14,6 +14,7 @@
 
 #include "access/xlog.h"
 #include "nodes/nodes.h"
+#include "port/atomics.h"
 #include "replication/syncrep.h"
 #include "storage/latch.h"
 #include "storage/shmem.h"
@@ -101,6 +102,8 @@ typedef struct
 	 */
 	bool		sync_standbys_defined;
 
+	pg_atomic_uint32 n_using_normal_slots;
+
 	WalSnd		walsnds[FLEXIBLE_ARRAY_MEMBER];
 } WalSndCtlData;