diff --git a/lib/nghttp2_buf.c b/lib/nghttp2_buf.c
index 87382518..55a1e07c 100644
--- a/lib/nghttp2_buf.c
+++ b/lib/nghttp2_buf.c
@@ -80,16 +80,6 @@ int nghttp2_buf_reserve(nghttp2_buf *buf, size_t new_cap)
   return 0;
 }
 
-int nghttp2_buf_pos_reserve(nghttp2_buf *buf, size_t new_rel_cap)
-{
-  return nghttp2_buf_reserve(buf, nghttp2_buf_pos_offset(buf) + new_rel_cap);
-}
-
-int nghttp2_buf_last_reserve(nghttp2_buf *buf, size_t new_rel_cap)
-{
-  return nghttp2_buf_reserve(buf, nghttp2_buf_last_offset(buf) + new_rel_cap);
-}
-
 void nghttp2_buf_reset(nghttp2_buf *buf)
 {
   buf->pos = buf->last = buf->mark = buf->begin;
diff --git a/lib/nghttp2_buf.h b/lib/nghttp2_buf.h
index 39300a55..12de863d 100644
--- a/lib/nghttp2_buf.h
+++ b/lib/nghttp2_buf.h
@@ -107,22 +107,6 @@ void nghttp2_buf_free(nghttp2_buf *buf);
  */
 int nghttp2_buf_reserve(nghttp2_buf *buf, size_t new_cap);
 
-/*
- * This function behaves like nghttp2_buf_reserve(), but new capacity
- * is calculated as nghttp2_buf_pos_offset(buf) + new_rel_cap. In
- * other words, this function reserves memory at least |new_rel_cap|
- * bytes from buf->pos.
- */
-int nghttp2_buf_pos_reserve(nghttp2_buf *buf, size_t new_rel_cap);
-
-/*
- * This function behaves like nghttp2_buf_reserve(), but new capacity
- * is calculated as nghttp2_buf_last_offset(buf) + new_rel_cap. In
- * other words, this function reserves memory at least |new_rel_cap|
- * bytes from buf->last.
- */
-int nghttp2_buf_last_reserve(nghttp2_buf *buf, size_t new_rel_cap);
-
 /*
  * Resets pos, last, mark member of |buf| to buf->begin.
  */
diff --git a/lib/nghttp2_helper.c b/lib/nghttp2_helper.c
index eb86b7b1..85a06e6e 100644
--- a/lib/nghttp2_helper.c
+++ b/lib/nghttp2_helper.c
@@ -55,23 +55,6 @@ uint32_t nghttp2_get_uint32(const uint8_t *data)
   return ntohl(n);
 }
 
-int nghttp2_reserve_buffer(uint8_t **buf_ptr, size_t *buflen_ptr,
-                           size_t min_length)
-{
-  if(min_length > *buflen_ptr) {
-    uint8_t *temp;
-    min_length = (min_length+4095)/4096*4096;
-    temp = realloc(*buf_ptr, min_length);
-    if(temp == NULL) {
-      return NGHTTP2_ERR_NOMEM;
-    } else {
-      *buf_ptr = temp;
-      *buflen_ptr = min_length;
-    }
-  }
-  return 0;
-}
-
 void* nghttp2_memdup(const void* src, size_t n)
 {
   void* dest;
diff --git a/lib/nghttp2_helper.h b/lib/nghttp2_helper.h
index d7d9c79e..8be6ce7d 100644
--- a/lib/nghttp2_helper.h
+++ b/lib/nghttp2_helper.h
@@ -58,25 +58,6 @@ uint16_t nghttp2_get_uint16(const uint8_t *data);
  */
 uint32_t nghttp2_get_uint32(const uint8_t *data);
 
-/*
- * Ensures that buffer |*buf_ptr| with |*buflen_ptr| length has at
- * least |min_length| bytes. If |min_length| > |*buflen_ptr|,
- * allocates new buffer having at least |min_length| bytes and assigns
- * its pointer to |*buf_ptr| and allocated number of bytes to
- * |*buflen_ptr|. The memory pointed by |*buf_ptr| previously may
- * change. No memory copy is done between old and new buffer.
- * |*buf_ptr| and |*buflen_ptr| are only updated iff this function
- * succeeds.
- *
- * This function returns 0 if it succeeds, or one of the following
- * negative error codes:
- *
- * NGHTTP2_ERR_NOMEM
- *     Out of memory.
- */
-int nghttp2_reserve_buffer(uint8_t **buf_ptr, size_t *buflen_ptr,
-                           size_t min_length);
-
 /*
  * Allocates |n| bytes of memory and copy the memory region pointed by
  * |src| with the length |n| bytes into it. Returns the allocated memory.
diff --git a/tests/main.c b/tests/main.c
index 6981124c..129224f8 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -317,8 +317,6 @@ int main(int argc, char* argv[])
       !CU_add_test(pSuite, "bufs_remove", test_nghttp2_bufs_remove) ||
       !CU_add_test(pSuite, "bufs_reset", test_nghttp2_bufs_reset) ||
       !CU_add_test(pSuite, "bufs_advance", test_nghttp2_bufs_advance) ||
-      !CU_add_test(pSuite, "bufs_seek_present",
-                   test_nghttp2_bufs_seek_last_present) ||
       !CU_add_test(pSuite, "bufs_next_present",
                    test_nghttp2_bufs_next_present) ||
       !CU_add_test(pSuite, "bufs_realloc", test_nghttp2_bufs_realloc)
diff --git a/tests/nghttp2_buf_test.c b/tests/nghttp2_buf_test.c
index f04f9c01..4eff4ea5 100644
--- a/tests/nghttp2_buf_test.c
+++ b/tests/nghttp2_buf_test.c
@@ -253,42 +253,6 @@ void test_nghttp2_bufs_advance(void)
   nghttp2_bufs_free(&bufs);
 }
 
-void test_nghttp2_bufs_seek_last_present(void)
-{
-  int rv;
-  nghttp2_bufs bufs;
-
-  rv = nghttp2_bufs_init(&bufs, 250, 3);
-  CU_ASSERT(0 == rv);
-
-  rv = nghttp2_bufs_advance(&bufs);
-  CU_ASSERT(0 == rv);
-
-  rv = nghttp2_bufs_addb(&bufs, 5);
-  CU_ASSERT(0 == rv);
-
-  bufs.cur = bufs.head;
-
-  /* cur is unchanged because cur is empty */
-  nghttp2_bufs_seek_last_present(&bufs);
-
-  CU_ASSERT(bufs.cur == bufs.head);
-
-  rv = nghttp2_bufs_addb(&bufs, 1);
-  CU_ASSERT(0 == rv);
-
-  nghttp2_bufs_seek_last_present(&bufs);
-
-  CU_ASSERT(bufs.cur == bufs.head->next);
-
-  /* cur is unchanged */
-  nghttp2_bufs_seek_last_present(&bufs);
-
-  CU_ASSERT(bufs.cur == bufs.head->next);
-
-  nghttp2_bufs_free(&bufs);
-}
-
 void test_nghttp2_bufs_next_present(void)
 {
   int rv;
diff --git a/tests/nghttp2_buf_test.h b/tests/nghttp2_buf_test.h
index 8a42ecad..5da388e7 100644
--- a/tests/nghttp2_buf_test.h
+++ b/tests/nghttp2_buf_test.h
@@ -31,7 +31,6 @@ void test_nghttp2_bufs_orb(void);
 void test_nghttp2_bufs_remove(void);
 void test_nghttp2_bufs_reset(void);
 void test_nghttp2_bufs_advance(void);
-void test_nghttp2_bufs_seek_last_present(void);
 void test_nghttp2_bufs_next_present(void);
 void test_nghttp2_bufs_realloc(void);