diff --git a/include/types/spoe.h b/include/types/spoe.h
index 9bba492..2dbf6e5 100644
--- a/include/types/spoe.h
+++ b/include/types/spoe.h
@@ -244,7 +244,6 @@
 	} timeout;
 
 	/* Config info */
-	char                 *engine_id;      /* engine-id string */
 	char                 *var_pfx;        /* Prefix used for vars set by the agent */
 	char                 *var_on_error;   /* Variable to set when an error occurred, in the TXN scope */
 	char                 *var_t_process;  /* Variable to set to report the processing time of the last event/group, in the TXN scope */
@@ -264,6 +263,7 @@
 
 	/* running info */
 	struct {
+		char           *engine_id;      /* engine-id string */
 		unsigned int    frame_size;     /* current maximum frame size, only used to encode messages */
 		unsigned int    processing;
 		struct freq_ctr processing_per_sec;
diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index 114ecf3..fe219ea 100644
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -172,7 +172,6 @@
 	free(agent->id);
 	free(agent->conf.file);
 	free(agent->var_pfx);
-	free(agent->engine_id);
 	free(agent->var_on_error);
 	free(agent->var_t_process);
 	free(agent->var_t_total);
@@ -185,8 +184,10 @@
 		spoe_release_group(grp);
 	}
 	if (agent->rt) {
-		for (i = 0; i < global.nbthread; ++i)
+		for (i = 0; i < global.nbthread; ++i) {
+			free(agent->rt[i].engine_id);
 			HA_SPIN_DESTROY(&agent->rt[i].lock);
+		}
 	}
 	free(agent->rt);
 	free(agent);
@@ -460,14 +461,14 @@
 		goto too_big;
 
 	/* (optionnal) "engine-id" K/V item, if present */
-	if (agent != NULL && agent->engine_id != NULL) {
+	if (agent != NULL && agent->rt[tid].engine_id != NULL) {
 		sz = SLEN(ENGINE_ID_KEY);
 		if (spoe_encode_buffer(ENGINE_ID_KEY, sz, &p, end) == -1)
 			goto too_big;
 
 		*p++ = SPOE_DATA_T_STR;
-		sz = strlen(agent->engine_id);
-		if (spoe_encode_buffer(agent->engine_id, sz, &p, end) == -1)
+		sz = strlen(agent->rt[tid].engine_id);
+		if (spoe_encode_buffer(agent->rt[tid].engine_id, sz, &p, end) == -1)
 			goto too_big;
 	}
 
@@ -3089,16 +3090,13 @@
 		return 1;
 	}
 
-	/* finish per-thread agent initialization */
-	if (global.nbthread == 1)
-		conf->agent->flags |= SPOE_FL_ASYNC;
-
 	if ((conf->agent->rt = calloc(global.nbthread, sizeof(*conf->agent->rt))) == NULL) {
 		ha_alert("Proxy %s : out of memory initializing SPOE agent '%s' declared at %s:%d.\n",
 			 px->id, conf->agent->id, conf->agent->conf.file, conf->agent->conf.line);
 		return 1;
 	}
 	for (i = 0; i < global.nbthread; ++i) {
+		conf->agent->rt[i].engine_id    = NULL;
 		conf->agent->rt[i].frame_size   = conf->agent->max_frame_size;
 		conf->agent->rt[i].processing   = 0;
 		LIST_INIT(&conf->agent->rt[i].applets);
@@ -3121,12 +3119,13 @@
 	struct spoe_config *conf = fconf->conf;
 	struct spoe_agent *agent = conf->agent;
 
-	if (agent->engine_id == NULL) {
+	/* Use a != seed per process */
+	if (relative_pid > 1 && tid == 0)
 		srandom(now_ms * pid);
-		agent->engine_id = generate_pseudo_uuid();
-		if (agent->engine_id == NULL)
-			return -1;
-	}
+
+	agent->rt[tid].engine_id = generate_pseudo_uuid();
+	if (agent->rt[tid].engine_id == NULL)
+		return -1;
 	return 0;
 }
 
@@ -3394,12 +3393,11 @@
 		curagent->timeout.idle       = TICK_ETERNITY;
 		curagent->timeout.processing = TICK_ETERNITY;
 
-		curagent->engine_id      = NULL;
 		curagent->var_pfx        = NULL;
 		curagent->var_on_error   = NULL;
 		curagent->var_t_process  = NULL;
 		curagent->var_t_total    = NULL;
-		curagent->flags          = (SPOE_FL_PIPELINING | SPOE_FL_SND_FRAGMENTATION);
+		curagent->flags          = (SPOE_FL_ASYNC | SPOE_FL_PIPELINING | SPOE_FL_SND_FRAGMENTATION);
 		curagent->cps_max        = 0;
 		curagent->eps_max        = 0;
 		curagent->max_frame_size = MAX_FRAME_SIZE;
@@ -3544,15 +3542,8 @@
 				goto out;
 			if (kwm == 1)
 				curagent->flags &= ~SPOE_FL_ASYNC;
-			else {
-				if (global.nbthread == 1)
-					curagent->flags |= SPOE_FL_ASYNC;
-				else {
-					ha_warning("parsing [%s:%d] Async option is not supported with threads.\n",
-						   file, linenum);
-					err_code |= ERR_WARN;
-				}
-			}
+			else
+				curagent->flags |= SPOE_FL_ASYNC;
 			goto out;
 		}
 		else if (!strcmp(args[1], "send-frag-payload")) {