diff --git a/lib/zlog.c b/lib/zlog.c
index 24800c6e64..a99fd71f0d 100644
--- a/lib/zlog.c
+++ b/lib/zlog.c
@@ -81,6 +81,11 @@ static gid_t zlog_gid = -1;
 DECLARE_ATOMLIST(zlog_targets, struct zlog_target, head);
 static struct zlog_targets_head zlog_targets;
 
+/* Global setting for buffered vs immediate output. The default is
+ * per-pthread buffering.
+ */
+static bool default_immediate;
+
 /* cf. zlog.h for additional comments on this struct.
  *
  * Note: you MUST NOT pass the format string + va_list to non-FRR format
@@ -395,7 +400,7 @@ static void vzlog_tls(struct zlog_tls *zlog_tls, const struct xref_logmsg *xref,
 	struct zlog_msg *msg;
 	char *buf;
 	bool ignoremsg = true;
-	bool immediate = false;
+	bool immediate = default_immediate;
 
 	/* avoid further processing cost if no target wants this message */
 	rcu_read_lock();
@@ -714,6 +719,14 @@ struct zlog_target *zlog_target_replace(struct zlog_target *oldzt,
 	return oldzt;
 }
 
+/*
+ * Enable or disable 'immediate' output - default is to buffer
+ * each pthread's messages.
+ */
+void zlog_set_immediate(bool set_p)
+{
+	default_immediate = set_p;
+}
 
 /* common init */
 
diff --git a/lib/zlog.h b/lib/zlog.h
index 66d8f1e5d7..2ef4173605 100644
--- a/lib/zlog.h
+++ b/lib/zlog.h
@@ -249,6 +249,9 @@ extern void zlog_tls_buffer_init(void);
 extern void zlog_tls_buffer_flush(void);
 extern void zlog_tls_buffer_fini(void);
 
+/* Enable or disable 'immediate' output - default is to buffer messages. */
+extern void zlog_set_immediate(bool set_p);
+
 #ifdef __cplusplus
 }
 #endif