diff --git a/lib/ngtcp2_acktr.c b/lib/ngtcp2_acktr.c
index e4c658a2c228d95e47c3dc14733108e41e3430b6..4ab9393a482f678203ededdfd1080f6e827250e4 100644
--- a/lib/ngtcp2_acktr.c
+++ b/lib/ngtcp2_acktr.c
@@ -58,7 +58,7 @@ int ngtcp2_acktr_init(ngtcp2_acktr *acktr, int delayed_ack, ngtcp2_log *log,
     return rv;
   }
 
-  rv = ngtcp2_ksl_init(&acktr->ent, greater, -1, mem);
+  rv = ngtcp2_ksl_init(&acktr->ents, greater, -1, mem);
   if (rv != 0) {
     ngtcp2_ringbuf_free(&acktr->acks);
     return rv;
@@ -82,11 +82,11 @@ void ngtcp2_acktr_free(ngtcp2_acktr *acktr) {
     return;
   }
 
-  for (it = ngtcp2_ksl_begin(&acktr->ent); !ngtcp2_ksl_it_end(&it);
+  for (it = ngtcp2_ksl_begin(&acktr->ents); !ngtcp2_ksl_it_end(&it);
        ngtcp2_ksl_it_next(&it)) {
     ngtcp2_acktr_entry_del(ngtcp2_ksl_it_get(&it), acktr->mem);
   }
-  ngtcp2_ksl_free(&acktr->ent);
+  ngtcp2_ksl_free(&acktr->ents);
 
   for (i = 0; i < acktr->acks.len; ++i) {
     ack_ent = ngtcp2_ringbuf_get(&acktr->acks, i);
@@ -101,14 +101,14 @@ int ngtcp2_acktr_add(ngtcp2_acktr *acktr, ngtcp2_acktr_entry *ent,
   ngtcp2_acktr_entry *delent;
   int rv;
 
-  it = ngtcp2_ksl_lower_bound(&acktr->ent, (int64_t)ent->pkt_num);
+  it = ngtcp2_ksl_lower_bound(&acktr->ents, (int64_t)ent->pkt_num);
   if (!ngtcp2_ksl_it_end(&it) &&
       ngtcp2_ksl_it_key(&it) == (int64_t)ent->pkt_num) {
     /* TODO What to do if we receive duplicated packet number? */
     return NGTCP2_ERR_INVALID_ARGUMENT;
   }
 
-  rv = ngtcp2_ksl_insert(&acktr->ent, NULL, (int64_t)ent->pkt_num, ent);
+  rv = ngtcp2_ksl_insert(&acktr->ents, NULL, (int64_t)ent->pkt_num, ent);
   if (rv != 0) {
     return rv;
   }
@@ -120,11 +120,11 @@ int ngtcp2_acktr_add(ngtcp2_acktr *acktr, ngtcp2_acktr_entry *ent,
     }
   }
 
-  if (ngtcp2_ksl_len(&acktr->ent) > NGTCP2_ACKTR_MAX_ENT) {
-    it = ngtcp2_ksl_end(&acktr->ent);
+  if (ngtcp2_ksl_len(&acktr->ents) > NGTCP2_ACKTR_MAX_ENT) {
+    it = ngtcp2_ksl_end(&acktr->ents);
     ngtcp2_ksl_it_prev(&it);
     delent = ngtcp2_ksl_it_get(&it);
-    ngtcp2_ksl_remove(&acktr->ent, NULL, (int64_t)delent->pkt_num);
+    ngtcp2_ksl_remove(&acktr->ents, NULL, (int64_t)delent->pkt_num);
     ngtcp2_acktr_entry_del(delent, acktr->mem);
   }
 
@@ -135,12 +135,12 @@ int ngtcp2_acktr_forget(ngtcp2_acktr *acktr, ngtcp2_acktr_entry *ent) {
   ngtcp2_ksl_it it;
   int rv;
 
-  it = ngtcp2_ksl_lower_bound(&acktr->ent, (int64_t)ent->pkt_num);
+  it = ngtcp2_ksl_lower_bound(&acktr->ents, (int64_t)ent->pkt_num);
   assert(ngtcp2_ksl_it_key(&it) == (int64_t)ent->pkt_num);
 
   for (; !ngtcp2_ksl_it_end(&it);) {
     ent = ngtcp2_ksl_it_get(&it);
-    rv = ngtcp2_ksl_remove(&acktr->ent, &it, (int64_t)ent->pkt_num);
+    rv = ngtcp2_ksl_remove(&acktr->ents, &it, (int64_t)ent->pkt_num);
     if (rv != 0) {
       return rv;
     }
@@ -151,7 +151,7 @@ int ngtcp2_acktr_forget(ngtcp2_acktr *acktr, ngtcp2_acktr_entry *ent) {
 }
 
 ngtcp2_ksl_it ngtcp2_acktr_get(ngtcp2_acktr *acktr) {
-  return ngtcp2_ksl_begin(&acktr->ent);
+  return ngtcp2_ksl_begin(&acktr->ents);
 }
 
 ngtcp2_acktr_ack_entry *ngtcp2_acktr_add_ack(ngtcp2_acktr *acktr,
@@ -188,7 +188,7 @@ static int acktr_remove(ngtcp2_acktr *acktr, ngtcp2_ksl_it *it,
                         ngtcp2_acktr_entry *ent) {
   int rv;
 
-  rv = ngtcp2_ksl_remove(&acktr->ent, it, (int64_t)ent->pkt_num);
+  rv = ngtcp2_ksl_remove(&acktr->ents, it, (int64_t)ent->pkt_num);
   if (rv != 0) {
     return rv;
   }
@@ -214,7 +214,7 @@ static int acktr_on_ack(ngtcp2_acktr *acktr, ngtcp2_ringbuf *rb,
   min_ack = largest_ack - fr->first_ack_blklen;
 
   /* Assume that ngtcp2_pkt_validate_ack(fr) returns 0 */
-  it = ngtcp2_ksl_lower_bound(&acktr->ent, (int64_t)largest_ack);
+  it = ngtcp2_ksl_lower_bound(&acktr->ents, (int64_t)largest_ack);
   if (ngtcp2_ksl_it_end(&it)) {
     goto fin;
   }
@@ -234,7 +234,7 @@ static int acktr_on_ack(ngtcp2_acktr *acktr, ngtcp2_ringbuf *rb,
     largest_ack = min_ack - fr->blks[i].gap - 2;
     min_ack = largest_ack - fr->blks[i].blklen;
 
-    it = ngtcp2_ksl_lower_bound(&acktr->ent, (int64_t)largest_ack);
+    it = ngtcp2_ksl_lower_bound(&acktr->ents, (int64_t)largest_ack);
     if (ngtcp2_ksl_it_end(&it)) {
       break;
     }
diff --git a/lib/ngtcp2_acktr.h b/lib/ngtcp2_acktr.h
index b2d41abd5d625db9f21f886b2e505a63ab44a607..5caedf5f1159d97d7a2df206960faad754f69ab2 100644
--- a/lib/ngtcp2_acktr.h
+++ b/lib/ngtcp2_acktr.h
@@ -105,9 +105,9 @@ typedef enum {
  */
 typedef struct {
   ngtcp2_ringbuf acks;
-  /* ent includes ngtcp2_acktr_entry sorted by decreasing order of
+  /* ents includes ngtcp2_acktr_entry sorted by decreasing order of
      packet number. */
-  ngtcp2_ksl ent;
+  ngtcp2_ksl ents;
   ngtcp2_log *log;
   ngtcp2_mem *mem;
   /* flags is bitwise OR of zero, or more of ngtcp2_ack_flag. */
@@ -132,8 +132,7 @@ int ngtcp2_acktr_init(ngtcp2_acktr *acktr, int delayed_ack, ngtcp2_log *log,
 
 /*
  * ngtcp2_acktr_free frees resources allocated for |acktr|.  It frees
- * any ngtcp2_acktr_entry directly or indirectly pointed by
- * acktr->ent.
+ * any ngtcp2_acktr_entry added to |acktr|.
  */
 void ngtcp2_acktr_free(ngtcp2_acktr *acktr);
 
diff --git a/tests/ngtcp2_acktr_test.c b/tests/ngtcp2_acktr_test.c
index c42d43fd339fb97f34764bee12372858072a6372..19a78a7f16d219d7426da14e43d8df6967631e17 100644
--- a/tests/ngtcp2_acktr_test.c
+++ b/tests/ngtcp2_acktr_test.c
@@ -65,7 +65,7 @@ void test_ngtcp2_acktr_add(void) {
   for (i = 0; i < arraylen(ents); ++i) {
     it = ngtcp2_acktr_get(&acktr);
     ent = ngtcp2_ksl_it_get(&it);
-    ngtcp2_ksl_remove(&acktr.ent, NULL, (int64_t)ent->pkt_num);
+    ngtcp2_ksl_remove(&acktr.ents, NULL, (int64_t)ent->pkt_num);
     ngtcp2_acktr_entry_del(ent, mem);
 
     it = ngtcp2_acktr_get(&acktr);
@@ -113,7 +113,7 @@ void test_ngtcp2_acktr_eviction(void) {
     ngtcp2_acktr_add(&acktr, ent, 1, 999 + i);
   }
 
-  CU_ASSERT(NGTCP2_ACKTR_MAX_ENT == ngtcp2_ksl_len(&acktr.ent));
+  CU_ASSERT(NGTCP2_ACKTR_MAX_ENT == ngtcp2_ksl_len(&acktr.ents));
 
   for (i = 0, it = ngtcp2_acktr_get(&acktr); !ngtcp2_ksl_it_end(&it);
        ++i, ngtcp2_ksl_it_next(&it)) {
@@ -132,7 +132,7 @@ void test_ngtcp2_acktr_eviction(void) {
     ngtcp2_acktr_add(&acktr, ent, 1, 999 + i);
   }
 
-  CU_ASSERT(NGTCP2_ACKTR_MAX_ENT == ngtcp2_ksl_len(&acktr.ent));
+  CU_ASSERT(NGTCP2_ACKTR_MAX_ENT == ngtcp2_ksl_len(&acktr.ents));
 
   for (i = 0, it = ngtcp2_acktr_get(&acktr); !ngtcp2_ksl_it_end(&it);
        ++i, ngtcp2_ksl_it_next(&it)) {
@@ -160,7 +160,7 @@ void test_ngtcp2_acktr_forget(void) {
     ngtcp2_acktr_add(&acktr, ent, 1, 999 + i);
   }
 
-  CU_ASSERT(7 == ngtcp2_ksl_len(&acktr.ent));
+  CU_ASSERT(7 == ngtcp2_ksl_len(&acktr.ents));
 
   it = ngtcp2_acktr_get(&acktr);
   ngtcp2_ksl_it_next(&it);
@@ -169,7 +169,7 @@ void test_ngtcp2_acktr_forget(void) {
   ent = ngtcp2_ksl_it_get(&it);
   ngtcp2_acktr_forget(&acktr, ent);
 
-  CU_ASSERT(3 == ngtcp2_ksl_len(&acktr.ent));
+  CU_ASSERT(3 == ngtcp2_ksl_len(&acktr.ents));
 
   it = ngtcp2_acktr_get(&acktr);
   ent = ngtcp2_ksl_it_get(&it);
@@ -191,7 +191,7 @@ void test_ngtcp2_acktr_forget(void) {
 
   ngtcp2_acktr_forget(&acktr, ent);
 
-  CU_ASSERT(0 == ngtcp2_ksl_len(&acktr.ent));
+  CU_ASSERT(0 == ngtcp2_ksl_len(&acktr.ents));
 
   ngtcp2_acktr_free(&acktr);
 }
@@ -245,7 +245,7 @@ void test_ngtcp2_acktr_recv_ack(void) {
   ngtcp2_acktr_recv_ack(&acktr, &ackfr, NULL, 1000000009);
 
   CU_ASSERT(0 == ngtcp2_ringbuf_len(&acktr.acks));
-  CU_ASSERT(5 == ngtcp2_ksl_len(&acktr.ent));
+  CU_ASSERT(5 == ngtcp2_ksl_len(&acktr.ents));
 
   it = ngtcp2_acktr_get(&acktr);
   ent = ngtcp2_ksl_it_get(&it);
diff --git a/tests/ngtcp2_conn_test.c b/tests/ngtcp2_conn_test.c
index 2843b600da0d22bc077de297d54414ab66a243c5..0c3e694086c761713c5025ab1e5de64a0cab4880 100644
--- a/tests/ngtcp2_conn_test.c
+++ b/tests/ngtcp2_conn_test.c
@@ -1801,7 +1801,7 @@ void test_ngtcp2_conn_recv_delayed_handshake_pkt(void) {
   rv = ngtcp2_conn_recv(conn, buf, pktlen, 1);
 
   CU_ASSERT(0 == rv);
-  CU_ASSERT(1 == ngtcp2_ksl_len(&conn->hs_pktns.acktr.ent));
+  CU_ASSERT(1 == ngtcp2_ksl_len(&conn->hs_pktns.acktr.ents));
   CU_ASSERT(conn->hs_pktns.acktr.flags & NGTCP2_ACKTR_FLAG_ACTIVE_ACK);
 
   ngtcp2_conn_del(conn);
@@ -1845,7 +1845,7 @@ void test_ngtcp2_conn_recv_delayed_handshake_pkt(void) {
   rv = ngtcp2_conn_recv(conn, buf, pktlen, 1);
 
   CU_ASSERT(0 == rv);
-  CU_ASSERT(1 == ngtcp2_ksl_len(&conn->hs_pktns.acktr.ent));
+  CU_ASSERT(1 == ngtcp2_ksl_len(&conn->hs_pktns.acktr.ents));
   CU_ASSERT(!conn->hs_pktns.acktr.flags);
 
   ngtcp2_conn_del(conn);
@@ -2978,7 +2978,7 @@ void test_ngtcp2_conn_pkt_payloadlen(void) {
   spktlen = ngtcp2_conn_handshake(conn, buf, sizeof(buf), buf, pktlen, ++t);
 
   CU_ASSERT(spktlen == 0);
-  CU_ASSERT(0 == ngtcp2_ksl_len(&conn->in_pktns.acktr.ent));
+  CU_ASSERT(0 == ngtcp2_ksl_len(&conn->in_pktns.acktr.ents));
 
   ngtcp2_conn_del(conn);
 }