diff --git a/src/scheduler/src/core_events.c b/src/scheduler/src/core_events.c
index 8a3c8693..c720afc2 100644
--- a/src/scheduler/src/core_events.c
+++ b/src/scheduler/src/core_events.c
@@ -834,6 +834,7 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
         switch (ev->type) {
         case XCE_CORE_EVENT_CONFIG_PUSH: {
             xce_conf4sched_t* config = ev->u.config_push.config;
+            xce_conf4sched_t* older  = core->config;
 
             core->config = config;
             core->configver++;
@@ -847,6 +848,12 @@ int xce_core_push_events(xce_sched_core_t* core, xce_core_event_t* events,
             if ((picker != NULL) && (picker->picker_iface->on_config != NULL)) {
                 picker->picker_iface->on_config(picker, config);
             }
+
+            /* bug-1886: the core owns its config; the replaced one is no
+             * longer referenced (everything built from it is a copy) */
+            if ((older != NULL) && (older != config)) {
+                free_Conf4Sched_ptr(&older);
+            }
             break;
         }
 
diff --git a/src/scheduler/src/scheduler.c b/src/scheduler/src/scheduler.c
index 50c9d93c..2ff1762b 100644
--- a/src/scheduler/src/scheduler.c
+++ b/src/scheduler/src/scheduler.c
@@ -1042,10 +1042,34 @@ static int sched_init_queues(xce_scheduler_t* sched)
     }
 
     for (i = 0; i < config->n_queues; i++) {
-        xce_sched_queue_t* q = make_sched_queue(sched, config->queues[i]);
+        xce_queue_t*       cq = config->queues[i];
+        xce_sched_queue_t* q  = NULL;
 
-        plugin_queue_update(sched, q);
-        sched_add_queue(&(sched->core), q);
+        if ((cq == NULL) || (cq->queue == NULL)) {
+            continue;
+        }
+
+        /* bug-1886: a re-applied config updates the registered queue in
+         * place (as QUEUE_UPDATE does, core_upsert_queue()). Building a
+         * new one made the add fail on the existing name, and the new,
+         * unregistered queue was handed to the picker and leaked while the
+         * registered one kept its old settings. */
+        q = sched_get_queue(&(sched->core), cq->queue);
+        if (q != NULL) {
+            q->attrs           = cq->attrs;
+            q->status          = cq->status;
+            q->priority        = cq->priority;
+            q->accept_interval = cq->accept_interval;
+            q->sched_delay     = cq->sched_delay;
+            plugin_queue_update(sched, q);
+        } else {
+            q = make_sched_queue(sched, cq);
+            if (q == NULL) {
+                continue;
+            }
+            plugin_queue_update(sched, q);
+            sched_add_queue(&(sched->core), q);
+        }
 
         if (picker != NULL) {
             picker->picker_iface->on_queue_update(picker, q);
@@ -1056,6 +1080,8 @@ static int sched_init_queues(xce_scheduler_t* sched)
 }
 int sched_init_config(xce_scheduler_t* sched, xce_conf4sched_t* config)
 {
+    xce_conf4sched_t* older;
+
     /* bug-1784: register the cluster's NAMED usergroups/hostgroups (from
      * users.yaml's "usergroups:"/hosts.yaml's "hostgroups:") into
      * core.ugmgr/core.hgmgr BEFORE plugin_config_update() below -- a limit
@@ -1067,6 +1093,7 @@ int sched_init_config(xce_scheduler_t* sched, xce_conf4sched_t* config)
     groupmgr_load_configs(sched->core.hgmgr, config->n_hgroups, config->hgroups);
 
     plugin_config_update(sched, config);
+    older              = sched->core.config;
     sched->core.config = config;
 
     sched_init_resources(sched);
@@ -1075,6 +1102,13 @@ int sched_init_config(xce_scheduler_t* sched, xce_conf4sched_t* config)
 
     sched->core.configver++; /* increase the version of configuration */
 
+    /* bug-1886: the core owns its config (freed in xce_sched_core_fini());
+     * the one this replaces is no longer referenced -- the queues,
+     * resources, groups and limits built from it are copies. */
+    if ((older != NULL) && (older != config)) {
+        free_Conf4Sched_ptr(&older);
+    }
+
     return 0;
 }
 
diff --git a/src/scheduler/testsuite/test_config_push_deferred.c b/src/scheduler/testsuite/test_config_push_deferred.c
index bcb16c90..b6a76c71 100644
--- a/src/scheduler/testsuite/test_config_push_deferred.c
+++ b/src/scheduler/testsuite/test_config_push_deferred.c
@@ -31,6 +31,10 @@
 
 #include <unity/unity.h>
 
+#if defined(__SANITIZE_ADDRESS__)
+#include <sanitizer/asan_interface.h>
+#endif
+
 #include "controller.capnp.h"
 #include "plugin.h"
 #include "resobj.h"
@@ -249,10 +253,83 @@ static void test_applied_config_push_is_recorded(void)
     printf("test_applied_config_push_is_recorded: PASS\n");
 }
 
+/* bug-1886: stashes and applies a config carrying one queue, QUEUE_NAME,
+ * at `priority`; returns the applied config. */
+static xce_conf4sched_t* apply_queue_config(xce_scheduler_t* sched,
+                                            int32_t          priority)
+{
+    xce_queue_t*      q      = (xce_queue_t*)calloc(1, sizeof(*q));
+    xce_queue_t**     queues = (xce_queue_t**)calloc(1, sizeof(*queues));
+    xce_conf4sched_t* config = (xce_conf4sched_t*)calloc(1, sizeof(*config));
+
+    TEST_ASSERT_NOT_NULL(q);
+    TEST_ASSERT_NOT_NULL(queues);
+    TEST_ASSERT_NOT_NULL(config);
+
+    q->queue         = strdup(QUEUE_NAME);
+    q->priority      = priority;
+    queues[0]        = q;
+    config->n_queues = 1;
+    config->queues   = queues;
+
+    TEST_ASSERT_EQUAL_INT(0, sched_stash_config(sched, config));
+    TEST_ASSERT_EQUAL_INT(1, sched_apply_pending_config(sched));
+    TEST_ASSERT_EQUAL_PTR(config, sched->core.config);
+
+    return config;
+}
+
+/*
+ * bug-1886: re-applying a config updates the registered queue in place
+ * (the rejected duplicate used to be built, handed to the picker and
+ * leaked, while the registered queue kept its old settings), and the
+ * config it replaces is freed.
+ */
+static xce_scheduler_t g_reapply_sched;
+
+static void test_config_reapply_updates_queue_in_place_and_frees_old(void)
+{
+    xce_sched_plugin_t* fcfs = NULL;
+    xce_sched_queue_t*  q_first;
+    xce_sched_queue_t*  q_second;
+    xce_conf4sched_t*   first;
+    int                 rc;
+
+    memset(&g_reapply_sched, 0, sizeof(g_reapply_sched));
+    rc = xce_sched_core_init(&(g_reapply_sched.core));
+    TEST_ASSERT_EQUAL_INT(0, rc);
+
+    fcfs = builtin_fcfs_new_plugin();
+    TEST_ASSERT_NOT_NULL(fcfs);
+    rc = plugin_register(&g_reapply_sched, fcfs);
+    TEST_ASSERT_TRUE(rc >= 0);
+    g_reapply_sched.core.job_pick_plugin = (char*)"builtin_fcfs";
+
+    first   = apply_queue_config(&g_reapply_sched, 1);
+    q_first = sched_get_queue(&(g_reapply_sched.core), QUEUE_NAME);
+    TEST_ASSERT_NOT_NULL(q_first);
+    TEST_ASSERT_EQUAL_INT(1, q_first->priority);
+
+    (void)apply_queue_config(&g_reapply_sched, 7);
+    q_second = sched_get_queue(&(g_reapply_sched.core), QUEUE_NAME);
+    TEST_ASSERT_EQUAL_PTR(q_first, q_second);
+    TEST_ASSERT_EQUAL_INT_MESSAGE(
+        7, q_second->priority,
+        "a re-applied config must update the registered queue in place");
+
+#if defined(__SANITIZE_ADDRESS__)
+    TEST_ASSERT_TRUE_MESSAGE(__asan_address_is_poisoned(first),
+                             "the replaced config must be freed");
+#else
+    (void)first;
+#endif
+}
+
 int main(void)
 {
     UNITY_BEGIN();
     RUN_TEST(test_config_push_mid_session_does_not_end_round);
     RUN_TEST(test_applied_config_push_is_recorded);
+    RUN_TEST(test_config_reapply_updates_queue_in_place_and_frees_old);
     return UNITY_END();
 }