diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 1bea0d9..c5692ba 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -401,7 +401,8 @@ SET ENABLE_SEQSCAN TO OFF;
         number of active concurrent connections is at least
         <varname>max_connections</> minus
         <varname>superuser_reserved_connections</varname>, new
-        connections will be accepted only for superusers.
+        connections will be accepted only for superusers, and no
+        new replication connections will be accepted.
        </para>
 
        <para>
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 40a196a..179d009 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -618,6 +618,37 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 	}
 
 	/*
+	 * If we're trying to shut down, only superusers can connect, and
+	 * new replication connections are not allowed.
+	 */
+	if ((!am_superuser || am_walsender) &&
+		MyProcPort != NULL &&
+		MyProcPort->canAcceptConnections == CAC_WAITBACKUP)
+	{
+		if (am_walsender)
+			ereport(FATAL,
+					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+		     	errmsg("new replication connections are not allowed during database shutdown")));
+		else
+			ereport(FATAL,
+					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				errmsg("must be superuser to connect during database shutdown")));
+	}
+
+	/*
+	 * The last few connections slots are reserved for superusers.
+	 * Although replication connections currently require superuser
+	 * privileges, we don't allow them to consume the reserved slots,
+	 * which are intended for interactive use.
+	 */
+	if ((!am_superuser || am_walsender) &&
+		ReservedBackends > 0 &&
+		!HaveNFreeProcs(ReservedBackends))
+		ereport(FATAL,
+				(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
+				 errmsg("remaining connection slots are reserved for non-replication superuser connections")));
+
+	/*
 	 * If walsender, we're done here --- we don't want to connect to any
 	 * particular database.
 	 */
@@ -779,26 +810,6 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 		CheckMyDatabase(dbname, am_superuser);
 
 	/*
-	 * If we're trying to shut down, only superusers can connect.
-	 */
-	if (!am_superuser &&
-		MyProcPort != NULL &&
-		MyProcPort->canAcceptConnections == CAC_WAITBACKUP)
-		ereport(FATAL,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-		   errmsg("must be superuser to connect during database shutdown")));
-
-	/*
-	 * Check a normal user hasn't connected to a superuser reserved slot.
-	 */
-	if (!am_superuser &&
-		ReservedBackends > 0 &&
-		!HaveNFreeProcs(ReservedBackends))
-		ereport(FATAL,
-				(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
-				 errmsg("connection limit exceeded for non-superusers")));
-
-	/*
 	 * Now process any command-line switches that were included in the startup
 	 * packet, if we are in a regular backend.	We couldn't do this before
 	 * because we didn't know if client is a superuser.