diff --git a/src/core/cfg_core.c b/src/core/cfg_core.c
index d0b409f158c..a23fb8afab0 100644
--- a/src/core/cfg_core.c
+++ b/src/core/cfg_core.c
@@ -113,7 +113,7 @@ struct cfg_group_core default_core_cfg = {
 	3, /*!< mem_summary -flags: 0 off, 1 pkg_status, 2 shm_status,
 		4 pkg_sums, 8 shm_sums, 16 short_status */
 	1, /*!< mem_safety - 0 disabled; 1 enabled */
-	0, /*!< mem_join - 0 disabled */
+	1, /*!< mem_join - 1 enabled */
 	0, /*!< mem_status_mode - 0 only free fragments, 1 all fragements */
 	L_ERR, /*!< corelog */
 	L_DBG, /*!< latency cfg log */
diff --git a/src/core/mem/f_malloc.c b/src/core/mem/f_malloc.c
index a157f03172c..836ba01219d 100644
--- a/src/core/mem/f_malloc.c
+++ b/src/core/mem/f_malloc.c
@@ -656,7 +656,7 @@ void fm_free(void* qmp, void* p)
 	f->mname=mname;
 #endif
 #ifdef MEM_JOIN_FREE
-	if(unlikely(cfg_get(core, core_cfg, mem_join)!=0))
+	if(likely(cfg_get(core, core_cfg, mem_join)!=0))
 		fm_join_frag(qm, f);
 #endif /*MEM_JOIN_FREE*/
 	fm_insert_free(qm, f);
diff --git a/src/core/mem/q_malloc.c b/src/core/mem/q_malloc.c
index 52d2ef722c3..b718dfa3bf3 100644
--- a/src/core/mem/q_malloc.c
+++ b/src/core/mem/q_malloc.c
@@ -529,7 +529,7 @@ void qm_free(void* qmp, void* p)
 	qm->real_used-=size;
 
 #ifdef MEM_JOIN_FREE
-	if(unlikely(cfg_get(core, core_cfg, mem_join)!=0)) {
+	if(likely(cfg_get(core, core_cfg, mem_join)!=0)) {
 		next=prev=0;
 		/* mark this fragment as used (might fall into the middle of joined frags)
 		 * to give us an extra chance of detecting a double free call (if the joined