diff --git a/include/haproxy/pool.h b/include/haproxy/pool.h
index 9f8658d54..2c3c7db55 100644
--- a/include/haproxy/pool.h
+++ b/include/haproxy/pool.h
@@ -111,6 +111,9 @@
 /* poison each newly allocated area with this byte if >= 0 */
 extern int mem_poison_byte;
 
+/* set of POOL_DBG_* flags */
+extern uint pool_debugging;
+
 void *pool_get_from_os(struct pool_head *pool);
 void pool_put_to_os(struct pool_head *pool, void *ptr);
 void *pool_alloc_nocache(struct pool_head *pool);
diff --git a/src/pool.c b/src/pool.c
index aca28efdc..8462accd0 100644
--- a/src/pool.c
+++ b/src/pool.c
@@ -37,6 +37,7 @@ THREAD_LOCAL size_t pool_cache_count = 0;                /* #cache objects   */
 
 static struct list pools __read_mostly = LIST_HEAD_INIT(pools);
 int mem_poison_byte __read_mostly = -1;
+uint pool_debugging __read_mostly = 0;                   /* set of POOL_DBG_* flags */
 
 #ifdef DEBUG_FAIL_ALLOC
 static int mem_fail_rate __read_mostly = 0;