diff --git a/doc/configuration.txt b/doc/configuration.txt
index 26683a596..1c42d065d 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -963,9 +963,12 @@ nbproc <number>
 
 nbthread <number>
   This setting is only available when support for threads was built in. It
-  creates <number> threads for each created processes. It means if HAProxy is
-  started in foreground, it only creates <number> threads for the first
-  process. See also "nbproc".
+  makes haproxy run on <number> threads. This is exclusive with "nbproc". While
+  "nbproc" historically used to be the only way to use multiple processors, it
+  also involved a number of shortcomings related to the lack of synchronization
+  between processes (health-checks, peers, stick-tables, stats, ...) which do
+  not affect threads. As such, any modern configuration is strongly encouraged
+  to migrate away from "nbproc" to "nbthread". See also "nbproc".
 
 pidfile <pidfile>
   Writes PIDs of all daemons into file <pidfile>. This option is equivalent to
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 4c8b1fea9..85d8dd53a 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -2200,6 +2200,12 @@ int check_config_validity()
 	if (!global.tune.requri_len)
 		global.tune.requri_len = REQURI_LEN;
 
+	if (global.nbproc > 1 && global.nbthread > 1) {
+		ha_alert("config : cannot enable multiple processes if multiple threads are configured. Please use either nbproc or nbthread but not both.\n");
+		err_code |= ERR_ALERT | ERR_FATAL;
+		goto out;
+	}
+
 	pool_head_requri = create_pool("requri", global.tune.requri_len , MEM_F_SHARED);
 
 	pool_head_capture = create_pool("capture", global.tune.cookie_len, MEM_F_SHARED);