diff --git a/src/cfgdiag.c b/src/cfgdiag.c
index f8e4a9e08..c3b05e5d6 100644
--- a/src/cfgdiag.c
+++ b/src/cfgdiag.c
@@ -8,6 +8,10 @@
 #include <haproxy/proxy.h>
 #include <haproxy/server.h>
 
+struct cookie_entry {
+	struct ebpt_node node;
+};
+
 /* Use this function to emit diagnostic.
  * This can be used as a shortcut to set value pointed by <ret> to 1 at the
  * same time.
@@ -41,43 +45,42 @@ static inline void *diag_alloc(size_t size)
  * value. Backup servers are not taken into account as it can be quite common to
  * share cookie values in this case.
  */
-static void check_server_cookies(int *ret)
+static void srv_diag_cookies(int *ret, struct server *srv, struct eb_root *cookies_tree)
 {
-	struct cookie_entry {
-		struct ebpt_node node;
-	};
+	struct ebpt_node *cookie_node;
 
+	/* do not take into account backup servers */
+	if (!srv->cookie || (srv->flags & SRV_F_BACKUP))
+		return;
+
+	cookie_node = ebis_lookup(cookies_tree, srv->cookie);
+	if (cookie_node) {
+		diag_warning(ret, "parsing [%s:%d] : 'server %s' : same cookie value is set for a previous non-backup server in the same backend, it may break connection persistence\n",
+		             srv->conf.file, srv->conf.line, srv->id);
+	}
+	else {
+		cookie_node = diag_alloc(sizeof(*cookie_node));
+		cookie_node->key = srv->cookie;
+		ebis_insert(cookies_tree, cookie_node);
+	}
+}
+
+/* Perform a series of diagnostics on every servers from the configuration. */
+static void run_servers_diag(int *ret)
+{
+	struct eb_root cookies_tree = EB_ROOT_UNIQUE;
+	struct ebpt_node *cookie_node;
 	struct proxy  *px;
 	struct server *srv;
 
-	struct eb_root cookies_tree = EB_ROOT_UNIQUE;
-	struct ebpt_node *cookie_node;
-	struct cookie_entry *cookie_entry;
-	struct ebpt_node *node;
-
 	for (px = proxies_list; px; px = px->next) {
-		for (srv = px->srv; srv; srv = srv->next) {
-			/* do not take into account backup servers */
-			if (!srv->cookie || (srv->flags & SRV_F_BACKUP))
-				continue;
+		for (srv = px->srv; srv; srv = srv->next)
+			srv_diag_cookies(ret, srv, &cookies_tree);
 
-			cookie_node = ebis_lookup(&cookies_tree, srv->cookie);
-			if (cookie_node) {
-				diag_warning(ret, "parsing [%s:%d] : 'server %s' : same cookie value is set for a previous non-backup server in the same backend, it may break connection persistence\n",
-				             srv->conf.file, srv->conf.line, srv->id);
-				continue;
-			}
-
-			cookie_entry = diag_alloc(sizeof(*cookie_entry));
-			cookie_entry->node.key = srv->cookie;
-			ebis_insert(&cookies_tree, &cookie_entry->node);
-		}
-
-		/* clear the tree and free its entries */
-		while ((node = ebpt_first(&cookies_tree))) {
-			cookie_entry = ebpt_entry(node, struct cookie_entry, node);
-			eb_delete(&node->node);
-			free(cookie_entry);
+		/* clear the cookies tree before passing to the next proxy */
+		while ((cookie_node = ebpt_first(&cookies_tree))) {
+			ebpt_delete(cookie_node);
+			free(cookie_node);
 		}
 	}
 }
@@ -91,7 +94,7 @@ int cfg_run_diagnostics()
 {
 	int ret = 0;
 
-	check_server_cookies(&ret);
+	run_servers_diag(&ret);
 
 	return ret;
 }