diff --git a/lib/nghttp2_hd.c b/lib/nghttp2_hd.c
index 33676efb..6161261a 100644
--- a/lib/nghttp2_hd.c
+++ b/lib/nghttp2_hd.c
@@ -273,12 +273,20 @@ static void hd_ringbuf_free(nghttp2_hd_ringbuf *ringbuf)
   free(ringbuf->buffer);
 }
 
-static size_t hd_ringbuf_push_front(nghttp2_hd_ringbuf *ringbuf,
-                                    nghttp2_hd_entry *ent)
+static int hd_ringbuf_push_front(nghttp2_hd_ringbuf *ringbuf,
+                                 nghttp2_hd_entry *ent)
 {
-  assert(ringbuf->len <= ringbuf->mask);
+  int rv;
+
+  rv = hd_ringbuf_reserve(ringbuf, ringbuf->len + 1);
+
+  if(rv != 0) {
+    return rv;
+  }
+
   ringbuf->buffer[--ringbuf->first & ringbuf->mask] = ent;
   ++ringbuf->len;
+
   return 0;
 }
 
@@ -852,8 +860,17 @@ static nghttp2_hd_entry* add_hd_table_incremental(nghttp2_hd_context *context,
        immediately evicted. */
     --new_ent->ref;
   } else {
+    rv = hd_ringbuf_push_front(&context->hd_table, new_ent);
+
+    if(rv != 0) {
+      --new_ent->ref;
+      nghttp2_hd_entry_free(new_ent);
+      free(new_ent);
+
+      return NULL;
+    }
+
     context->hd_table_bufsize += room;
-    hd_ringbuf_push_front(&context->hd_table, new_ent);
 
     new_ent->flags |= NGHTTP2_HD_FLAG_REFSET;
   }
@@ -950,14 +967,8 @@ static void hd_context_shrink_table_size(nghttp2_hd_context *context)
 int nghttp2_hd_deflate_change_table_size(nghttp2_hd_deflater *deflater,
                                          size_t settings_hd_table_bufsize_max)
 {
-  int rv;
   size_t next_bufsize = nghttp2_min(settings_hd_table_bufsize_max,
                                     deflater->deflate_hd_table_bufsize_max);
-  rv = hd_ringbuf_reserve
-    (&deflater->ctx.hd_table, next_bufsize / NGHTTP2_HD_ENTRY_OVERHEAD);
-  if(rv != 0) {
-    return rv;
-  }
 
   deflater->ctx.hd_table_bufsize_max = next_bufsize;
 
@@ -970,14 +981,6 @@ int nghttp2_hd_deflate_change_table_size(nghttp2_hd_deflater *deflater,
 int nghttp2_hd_inflate_change_table_size(nghttp2_hd_inflater *inflater,
                                          size_t settings_hd_table_bufsize_max)
 {
-  int rv;
-
-  rv = hd_ringbuf_reserve
-    (&inflater->ctx.hd_table,
-     settings_hd_table_bufsize_max / NGHTTP2_HD_ENTRY_OVERHEAD);
-  if(rv != 0) {
-    return rv;
-  }
   inflater->settings_hd_table_bufsize_max = settings_hd_table_bufsize_max;
   inflater->ctx.hd_table_bufsize_max = settings_hd_table_bufsize_max;
   hd_context_shrink_table_size(&inflater->ctx);
diff --git a/tests/main.c b/tests/main.c
index 659d19b9..042a86be 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -273,6 +273,8 @@ int main(int argc, char* argv[])
                    test_nghttp2_hd_inflate_clearall_inc) ||
       !CU_add_test(pSuite, "hd_inflate_zero_length_huffman",
                    test_nghttp2_hd_inflate_zero_length_huffman) ||
+      !CU_add_test(pSuite, "hd_ringbuf_reserve",
+                   test_nghttp2_hd_ringbuf_reserve) ||
       !CU_add_test(pSuite, "hd_change_table_size",
                    test_nghttp2_hd_change_table_size) ||
       !CU_add_test(pSuite, "hd_deflate_inflate",
diff --git a/tests/nghttp2_hd_test.c b/tests/nghttp2_hd_test.c
index 62ea279a..f2309d31 100644
--- a/tests/nghttp2_hd_test.c
+++ b/tests/nghttp2_hd_test.c
@@ -641,6 +641,57 @@ void test_nghttp2_hd_inflate_zero_length_huffman(void)
   nghttp2_hd_inflate_free(&inflater);
 }
 
+void test_nghttp2_hd_ringbuf_reserve(void)
+{
+  nghttp2_hd_deflater deflater;
+  nghttp2_hd_inflater inflater;
+  nghttp2_nv nv;
+  nghttp2_bufs bufs;
+  nva_out out;
+  int i;
+  ssize_t rv;
+  ssize_t blocklen;
+
+  frame_pack_bufs_init(&bufs);
+  nva_out_init(&out);
+
+  nv.flags = NGHTTP2_NV_FLAG_NONE;
+  nv.name = (uint8_t*)"a";
+  nv.namelen = strlen((const char*)nv.name);
+  nv.valuelen = 4;
+  nv.value = malloc(nv.valuelen);
+  memset(nv.value, 0, nv.valuelen);
+
+  nghttp2_hd_deflate_init2(&deflater, 8000);
+  nghttp2_hd_inflate_init(&inflater);
+
+  nghttp2_hd_inflate_change_table_size(&inflater, 8000);
+  nghttp2_hd_deflate_change_table_size(&deflater, 8000);
+
+  for(i = 0; i < 150; ++i) {
+    memcpy(nv.value, &i, sizeof(i));
+    rv = nghttp2_hd_deflate_hd_bufs(&deflater, &bufs, &nv, 1);
+    blocklen = nghttp2_bufs_len(&bufs);
+
+    CU_ASSERT(0 == rv);
+    CU_ASSERT(blocklen > 0);
+
+    CU_ASSERT(blocklen == inflate_hd(&inflater, &out, &bufs, 0));
+
+    CU_ASSERT(1 == out.nvlen);
+    assert_nv_equal(&nv, out.nva, 1);
+
+    nva_out_reset(&out);
+    nghttp2_bufs_reset(&bufs);
+  }
+
+  nghttp2_bufs_free(&bufs);
+  nghttp2_hd_inflate_free(&inflater);
+  nghttp2_hd_deflate_free(&deflater);
+
+  free(nv.value);
+}
+
 void test_nghttp2_hd_change_table_size(void)
 {
   nghttp2_hd_deflater deflater;
@@ -663,10 +714,8 @@ void test_nghttp2_hd_change_table_size(void)
   CU_ASSERT(0 == nghttp2_hd_inflate_change_table_size(&inflater, 8000));
   CU_ASSERT(0 == nghttp2_hd_deflate_change_table_size(&deflater, 8000));
 
-  CU_ASSERT(127 == deflater.ctx.hd_table.mask);
   CU_ASSERT(4096 == deflater.ctx.hd_table_bufsize_max);
 
-  CU_ASSERT(255 == inflater.ctx.hd_table.mask);
   CU_ASSERT(8000 == inflater.ctx.hd_table_bufsize_max);
   CU_ASSERT(8000 == inflater.settings_hd_table_bufsize_max);
 
@@ -691,10 +740,8 @@ void test_nghttp2_hd_change_table_size(void)
   CU_ASSERT(0 == nghttp2_hd_inflate_change_table_size(&inflater, 1024));
   CU_ASSERT(0 == nghttp2_hd_deflate_change_table_size(&deflater, 1024));
 
-  CU_ASSERT(127 == deflater.ctx.hd_table.mask);
   CU_ASSERT(1024 == deflater.ctx.hd_table_bufsize_max);
 
-  CU_ASSERT(255 == inflater.ctx.hd_table.mask);
   CU_ASSERT(1024 == inflater.ctx.hd_table_bufsize_max);
   CU_ASSERT(1024 == inflater.settings_hd_table_bufsize_max);
 
@@ -718,11 +765,9 @@ void test_nghttp2_hd_change_table_size(void)
   CU_ASSERT(0 == nghttp2_hd_inflate_change_table_size(&inflater, 0));
   CU_ASSERT(0 == nghttp2_hd_deflate_change_table_size(&deflater, 0));
 
-  CU_ASSERT(127 == deflater.ctx.hd_table.mask);
   CU_ASSERT(0 == deflater.ctx.hd_table.len);
   CU_ASSERT(0 == deflater.ctx.hd_table_bufsize_max);
 
-  CU_ASSERT(255 == inflater.ctx.hd_table.mask);
   CU_ASSERT(0 == inflater.ctx.hd_table.len);
   CU_ASSERT(0 == inflater.ctx.hd_table_bufsize_max);
   CU_ASSERT(0 == inflater.settings_hd_table_bufsize_max);
@@ -757,10 +802,8 @@ void test_nghttp2_hd_change_table_size(void)
   CU_ASSERT(0 == nghttp2_hd_inflate_change_table_size(&inflater, 8000));
   CU_ASSERT(0 == nghttp2_hd_deflate_change_table_size(&deflater, 8000));
 
-  CU_ASSERT(255 == deflater.ctx.hd_table.mask);
   CU_ASSERT(8000 == deflater.ctx.hd_table_bufsize_max);
 
-  CU_ASSERT(255 == inflater.ctx.hd_table.mask);
   CU_ASSERT(8000 == inflater.ctx.hd_table_bufsize_max);
   CU_ASSERT(8000 == inflater.settings_hd_table_bufsize_max);
 
@@ -783,10 +826,8 @@ void test_nghttp2_hd_change_table_size(void)
   CU_ASSERT(0 == nghttp2_hd_inflate_change_table_size(&inflater, 16383));
   CU_ASSERT(0 == nghttp2_hd_deflate_change_table_size(&deflater, 16383));
 
-  CU_ASSERT(255 == deflater.ctx.hd_table.mask);
   CU_ASSERT(8192 == deflater.ctx.hd_table_bufsize_max);
 
-  CU_ASSERT(511 == inflater.ctx.hd_table.mask);
   CU_ASSERT(16383 == inflater.ctx.hd_table_bufsize_max);
   CU_ASSERT(16383 == inflater.settings_hd_table_bufsize_max);
 
@@ -823,7 +864,6 @@ void test_nghttp2_hd_change_table_size(void)
   nghttp2_hd_deflate_init2(&deflater, 1024);
   nghttp2_hd_inflate_init(&inflater);
 
-  CU_ASSERT(127 == deflater.ctx.hd_table.mask);
   CU_ASSERT(1024 == deflater.ctx.hd_table_bufsize_max);
 
   /* This emits context update with buffer size 1024 */
diff --git a/tests/nghttp2_hd_test.h b/tests/nghttp2_hd_test.h
index 237751ba..51bf4ed6 100644
--- a/tests/nghttp2_hd_test.h
+++ b/tests/nghttp2_hd_test.h
@@ -37,6 +37,7 @@ void test_nghttp2_hd_inflate_newname_noinc(void);
 void test_nghttp2_hd_inflate_newname_inc(void);
 void test_nghttp2_hd_inflate_clearall_inc(void);
 void test_nghttp2_hd_inflate_zero_length_huffman(void);
+void test_nghttp2_hd_ringbuf_reserve(void);
 void test_nghttp2_hd_change_table_size(void);
 void test_nghttp2_hd_deflate_inflate(void);
 void test_nghttp2_hd_no_index(void);