diff --git a/src/proto_http.c b/src/proto_http.c
index e68b0e2f5..695ff7e33 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -1750,12 +1750,14 @@ resume_execution:
 			value->area[value->data] = '\0';
 
 			/* perform update */
+			HA_SPIN_LOCK(PATREF_LOCK, &ref->lock);
 			if (pat_ref_find_elt(ref, key->area) != NULL)
 				/* update entry if it exists */
 				pat_ref_set(ref, key->area, value->area, NULL);
 			else
 				/* insert a new entry */
 				pat_ref_add(ref, key->area, value->area, NULL);
+			HA_SPIN_UNLOCK(PATREF_LOCK, &ref->lock);
 
 			free_trash_chunk(key);
 			free_trash_chunk(value);
@@ -2058,8 +2060,10 @@ resume_execution:
 
 			/* perform update */
 			/* check if the entry already exists */
+			HA_SPIN_LOCK(PATREF_LOCK, &ref->lock);
 			if (pat_ref_find_elt(ref, key->area) == NULL)
 				pat_ref_add(ref, key->area, NULL, NULL);
+			HA_SPIN_UNLOCK(PATREF_LOCK, &ref->lock);
 
 			free_trash_chunk(key);
 			break;
diff --git a/src/proto_htx.c b/src/proto_htx.c
index 5643c625a..d2c03e180 100644
--- a/src/proto_htx.c
+++ b/src/proto_htx.c
@@ -2977,13 +2977,14 @@ static enum rule_result htx_req_get_intercept_rule(struct proxy *px, struct list
 				value->area[value->data] = '\0';
 
 				/* perform update */
+				HA_SPIN_LOCK(PATREF_LOCK, &ref->lock);
 				if (pat_ref_find_elt(ref, key->area) != NULL)
 					/* update entry if it exists */
 					pat_ref_set(ref, key->area, value->area, NULL);
 				else
 					/* insert a new entry */
 					pat_ref_add(ref, key->area, value->area, NULL);
-
+				HA_SPIN_UNLOCK(PATREF_LOCK, &ref->lock);
 				free_trash_chunk(key);
 				free_trash_chunk(value);
 				break;
@@ -3272,9 +3273,10 @@ resume_execution:
 
 				/* perform update */
 				/* check if the entry already exists */
+				HA_SPIN_LOCK(PATREF_LOCK, &ref->lock);
 				if (pat_ref_find_elt(ref, key->area) == NULL)
 					pat_ref_add(ref, key->area, NULL, NULL);
-
+				HA_SPIN_UNLOCK(PATREF_LOCK, &ref->lock);
 				free_trash_chunk(key);
 				break;
 			}