diff --git a/CHANGELOG.md b/CHANGELOG.md
index c3a90086b4..68522ecff3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 ### Fixes
 
 - [#1829](https://github.com/poanetwork/blockscout/pull/1829) - Handle nil quantities in block decoding routine
+- [#1830](https://github.com/poanetwork/blockscout/pull/1830) - Make block size field nullable
 
 ### Chore
 
@@ -43,6 +44,7 @@
  - [#1802](https://github.com/poanetwork/blockscout/pull/1802) - make coinmarketcap's number of pages configurable
  - [#1799](https://github.com/poanetwork/blockscout/pull/1799) - Use eth_getUncleByBlockHashAndIndex for uncle block fetching
  - [#1531](https://github.com/poanetwork/blockscout/pull/1531) - docker: fix dockerFile for secp256k1 building
+ - [#1835](https://github.com/poanetwork/blockscout/pull/1835) - fix: ignore `pong` messages without error
 
 ### Chore
 
diff --git a/apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/web_socket/web_socket_client.ex b/apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/web_socket/web_socket_client.ex
index e4e6d2ac8c..baa4ce61c1 100644
--- a/apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/web_socket/web_socket_client.ex
+++ b/apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/web_socket/web_socket_client.ex
@@ -152,6 +152,11 @@ defmodule EthereumJSONRPC.WebSocket.WebSocketClient do
   @impl :websocket_client
   def websocket_handle({:ping, ""}, _request, %__MODULE__{} = state), do: {:reply, {:pong, ""}, state}
 
+  @impl :websocket_client
+  def websocket_handle({:pong, _}, _request, state) do
+    {:ok, state}
+  end
+
   @impl :websocket_client
   def websocket_info({:"$gen_call", from, request}, _, %__MODULE__{} = state) do
     case handle_call(request, from, state) do
diff --git a/apps/explorer/lib/explorer/chain/block.ex b/apps/explorer/lib/explorer/chain/block.ex
index 974f1531bb..58d187d9d8 100644
--- a/apps/explorer/lib/explorer/chain/block.ex
+++ b/apps/explorer/lib/explorer/chain/block.ex
@@ -10,10 +10,9 @@ defmodule Explorer.Chain.Block do
   alias Explorer.Chain.{Address, Gas, Hash, Transaction}
   alias Explorer.Chain.Block.{Reward, SecondDegreeRelation}
 
-  @optional_attrs ~w(internal_transactions_indexed_at)a
+  @optional_attrs ~w(internal_transactions_indexed_at size)a
 
-  @required_attrs ~w(consensus difficulty gas_limit gas_used hash miner_hash nonce number parent_hash size timestamp
-                     total_difficulty)a
+  @required_attrs ~w(consensus difficulty gas_limit gas_used hash miner_hash nonce number parent_hash timestamp total_difficulty)a
 
   @typedoc """
   How much work is required to find a hash with some number of leading 0s.  It is measured in hashes for PoW
diff --git a/apps/explorer/priv/repo/migrations/20190424170833_change_block_size_to_nullable.exs b/apps/explorer/priv/repo/migrations/20190424170833_change_block_size_to_nullable.exs
new file mode 100644
index 0000000000..90769c7233
--- /dev/null
+++ b/apps/explorer/priv/repo/migrations/20190424170833_change_block_size_to_nullable.exs
@@ -0,0 +1,15 @@
+defmodule Explorer.Repo.Migrations.ChangeBlockSizeToNullable do
+  use Ecto.Migration
+
+  def up do
+    alter table(:blocks) do
+      modify(:size, :integer, null: true)
+    end
+  end
+
+  def down do
+    alter table(:blocks) do
+      modify(:size, :integer, null: false)
+    end
+  end
+end