diff --git a/include/haproxy/pattern-t.h b/include/haproxy/pattern-t.h
index 1d1de602f..803620d78 100644
--- a/include/haproxy/pattern-t.h
+++ b/include/haproxy/pattern-t.h
@@ -104,6 +104,7 @@ struct pat_ref {
 	char *reference; /* The reference name. */
 	char *display; /* String displayed to identify the pattern origin. */
 	struct list head; /* The head of the list of struct pat_ref_elt. */
+	struct eb_root ebpt_root; /* The tree where pattern reference elements are attached. */
 	struct list pat; /* The head of the list of struct pattern_expr. */
 	unsigned int flags; /* flags PAT_REF_*. */
 	unsigned int curr_gen; /* current generation number (anything below can be removed) */
@@ -120,6 +121,7 @@ struct pat_ref {
  */
 struct pat_ref_elt {
 	struct list list; /* Used to chain elements. */
+	struct ebpt_node node; /* Node to attach this element to its <pat_ref> ebtree. */
 	struct list back_refs; /* list of users tracking this pat ref */
 	void *list_head; /* all &pattern_list->from_ref derived from this reference, ends with NULL */
 	void *tree_head; /* all &pattern_tree->from_ref derived from this reference, ends with NULL */
diff --git a/include/haproxy/pattern.h b/include/haproxy/pattern.h
index be4106f1e..ab56711af 100644
--- a/include/haproxy/pattern.h
+++ b/include/haproxy/pattern.h
@@ -185,7 +185,7 @@ struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, con
 struct pat_ref_elt *pat_ref_load(struct pat_ref *ref, unsigned int gen, const char *pattern, const char *sample, int line, char **err);
 int pat_ref_push(struct pat_ref_elt *elt, struct pattern_expr *expr, int patflags, char **err);
 int pat_ref_add(struct pat_ref *ref, const char *pattern, const char *sample, char **err);
-int pat_ref_set(struct pat_ref *ref, const char *pattern, const char *sample, char **err);
+int pat_ref_set(struct pat_ref *ref, const char *pattern, const char *sample, char **err, struct pat_ref_elt *elt);
 int pat_ref_set_by_id(struct pat_ref *ref, struct pat_ref_elt *refelt, const char *value, char **err);
 int pat_ref_delete(struct pat_ref *ref, const char *key);
 void pat_ref_delete_by_ptr(struct pat_ref *ref, struct pat_ref_elt *elt);
diff --git a/src/hlua.c b/src/hlua.c
index 7b682c7ff..30a871315 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -1956,7 +1956,7 @@ static int hlua_set_map(lua_State *L)
 
 	HA_SPIN_LOCK(PATREF_LOCK, &ref->lock);
 	if (pat_ref_find_elt(ref, key) != NULL)
-		pat_ref_set(ref, key, value, NULL);
+		pat_ref_set(ref, key, value, NULL, NULL);
 	else
 		pat_ref_add(ref, key, value, NULL);
 	HA_SPIN_UNLOCK(PATREF_LOCK, &ref->lock);
diff --git a/src/http_act.c b/src/http_act.c
index 2505ad212..e81509587 100644
--- a/src/http_act.c
+++ b/src/http_act.c
@@ -1847,6 +1847,9 @@ static enum act_return http_action_set_map(struct act_rule *rule, struct proxy *
 		break;
 
 	case 1: // set-map
+	{
+		struct pat_ref_elt *elt;
+
 		/* allocate value */
 		value = alloc_trash_chunk();
 		if (!value)
@@ -1857,9 +1860,10 @@ static enum act_return http_action_set_map(struct act_rule *rule, struct proxy *
 		value->area[value->data] = '\0';
 
 		HA_SPIN_LOCK(PATREF_LOCK, &ref->lock);
-		if (pat_ref_find_elt(ref, key->area) != NULL) {
+		elt = pat_ref_find_elt(ref, key->area);
+		if (elt) {
 			/* update entry if it exists */
-			pat_ref_set(ref, key->area, value->area, NULL);
+			pat_ref_set(ref, key->area, value->area, NULL, elt);
 		}
 		else {
 			/* insert a new entry */
@@ -1867,6 +1871,7 @@ static enum act_return http_action_set_map(struct act_rule *rule, struct proxy *
 		}
 		HA_SPIN_UNLOCK(PATREF_LOCK, &ref->lock);
 		break;
+	}
 
 	case 2: // del-acl
 	case 3: // del-map
diff --git a/src/map.c b/src/map.c
index fe694b5fc..f4e74fb99 100644
--- a/src/map.c
+++ b/src/map.c
@@ -794,7 +794,7 @@ static int cli_parse_set_map(char **args, char *payload, struct appctx *appctx,
 			 */
 			err = NULL;
 			HA_SPIN_LOCK(PATREF_LOCK, &ctx->ref->lock);
-			if (!pat_ref_set(ctx->ref, args[3], args[4], &err)) {
+			if (!pat_ref_set(ctx->ref, args[3], args[4], &err, NULL)) {
 				HA_SPIN_UNLOCK(PATREF_LOCK, &ctx->ref->lock);
 				if (err)
 					return cli_dynerr(appctx, memprintf(&err, "%s.\n", err));
diff --git a/src/pattern.c b/src/pattern.c
index ce0f07b40..c77d23608 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -14,6 +14,8 @@
 #include <stdio.h>
 #include <errno.h>
 
+#include <import/ebistree.h>
+#include <import/ebpttree.h>
 #include <import/ebsttree.h>
 #include <import/lru.h>
 
@@ -1624,6 +1626,7 @@ void pat_ref_delete_by_ptr(struct pat_ref *ref, struct pat_ref_elt *elt)
 		HA_RWLOCK_WRUNLOCK(PATEXP_LOCK, &expr->lock);
 
 	LIST_DELETE(&elt->list);
+	ebpt_delete(&elt->node);
 	free(elt->sample);
 	free(elt->pattern);
 	free(elt);
@@ -1673,12 +1676,11 @@ int pat_ref_delete(struct pat_ref *ref, const char *key)
  */
 struct pat_ref_elt *pat_ref_find_elt(struct pat_ref *ref, const char *key)
 {
-	struct pat_ref_elt *elt;
+	struct ebpt_node *node;
 
-	list_for_each_entry(elt, &ref->head, list) {
-		if (strcmp(key, elt->pattern) == 0)
-			return elt;
-	}
+	node = ebis_lookup(&ref->ebpt_root, key);
+	if (node)
+		return ebpt_entry(node, struct pat_ref_elt, node);
 
 	return NULL;
 }
@@ -1759,12 +1761,12 @@ int pat_ref_set_by_id(struct pat_ref *ref, struct pat_ref_elt *refelt, const cha
 /* This function modifies to <value> the sample of all patterns matching <key>
  * under <ref>.
  */
-int pat_ref_set(struct pat_ref *ref, const char *key, const char *value, char **err)
+int pat_ref_set(struct pat_ref *ref, const char *key, const char *value, char **err, struct pat_ref_elt *elt)
 {
-	struct pat_ref_elt *elt;
 	int found = 0;
 	char *_merr;
 	char **merr;
+	struct ebpt_node *node;
 
 	if (err) {
 		merr = &_merr;
@@ -1773,21 +1775,28 @@ int pat_ref_set(struct pat_ref *ref, const char *key, const char *value, char **
 	else
 		merr = NULL;
 
-	/* Look for pattern in the reference. */
-	list_for_each_entry(elt, &ref->head, list) {
-		if (strcmp(key, elt->pattern) == 0) {
-			if (!pat_ref_set_elt(ref, elt, value, merr)) {
-				if (err && merr) {
-					if (!found) {
-						*err = *merr;
-					} else {
-						memprintf(err, "%s, %s", *err, *merr);
-						ha_free(merr);
-					}
+	if (elt) {
+		node = &elt->node;
+	}
+	else {
+		/* Look for pattern in the reference. */
+		node = ebis_lookup(&ref->ebpt_root, key);
+	}
+
+	while (node) {
+		elt = ebpt_entry(node, struct pat_ref_elt, node);
+		node = ebpt_next_dup(node);
+		if (!pat_ref_set_elt(ref, elt, value, merr)) {
+			if (err && merr) {
+				if (!found) {
+					*err = *merr;
+				} else {
+					memprintf(err, "%s, %s", *err, *merr);
+					ha_free(merr);
 				}
 			}
-			found = 1;
 		}
+		found = 1;
 	}
 
 	if (!found) {
@@ -1832,6 +1841,7 @@ struct pat_ref *pat_ref_new(const char *reference, const char *display, unsigned
 	ref->entry_cnt = 0;
 
 	LIST_INIT(&ref->head);
+	ref->ebpt_root = EB_ROOT;
 	LIST_INIT(&ref->pat);
 	HA_SPIN_INIT(&ref->lock);
 	LIST_APPEND(&pattern_reference, &ref->list);
@@ -1868,6 +1878,7 @@ struct pat_ref *pat_ref_newid(int unique_id, const char *display, unsigned int f
 	ref->next_gen = 0;
 	ref->unique_id = unique_id;
 	LIST_INIT(&ref->head);
+	ref->ebpt_root = EB_ROOT;
 	LIST_INIT(&ref->pat);
 	HA_SPIN_INIT(&ref->lock);
 	LIST_APPEND(&pattern_reference, &ref->list);
@@ -1905,6 +1916,8 @@ struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, con
 	elt->list_head = NULL;
 	elt->tree_head = NULL;
 	LIST_APPEND(&ref->head, &elt->list);
+	elt->node.key = elt->pattern;
+	ebis_insert(&ref->ebpt_root, &elt->node);
 	return elt;
  fail:
 	if (elt)
@@ -2075,6 +2088,7 @@ int pat_ref_purge_range(struct pat_ref *ref, uint from, uint to, int budget)
 		pat_delete_gen(ref, elt);
 
 		LIST_DELETE(&elt->list);
+		ebpt_delete(&elt->node);
 		free(elt->pattern);
 		free(elt->sample);
 		free(elt);