diff --git a/src/p2pool.cpp b/src/p2pool.cpp
index d89bc44..91b0f6a 100644
--- a/src/p2pool.cpp
+++ b/src/p2pool.cpp
@@ -158,6 +158,13 @@ p2pool::p2pool(int argc, char* argv[])
 	}
 	m_reconnectToHostAsync.data = this;
 
+	err = uv_async_init(uv_default_loop_checked(), &m_getMissingHeightsAsync, on_get_missing_heights);
+	if (err) {
+		LOGERR(1, "uv_async_init failed, error " << uv_err_name(err));
+		throw std::exception();
+	}
+	m_getMissingHeightsAsync.data = this;
+
 	uv_rwlock_init_checked(&m_mainchainLock);
 	uv_rwlock_init_checked(&m_minerDataLock);
 #ifndef P2POOL_UNIT_TESTS
@@ -179,6 +186,8 @@ p2pool::p2pool(int argc, char* argv[])
 	uv_mutex_init_checked(&m_submitBlockDataLock);
 	uv_mutex_init_checked(&m_submitAuxBlockDataLock);
 
+	uv_mutex_init_checked(&m_missingHeightsLock);
+
 	m_api = p->m_apiPath.empty() ? nullptr : new p2pool_api(p->m_apiPath, p->m_localStats);
 
 	if (p->m_localStats && !m_api) {
@@ -264,6 +273,8 @@ p2pool::~p2pool()
 	uv_mutex_destroy(&m_submitBlockDataLock);
 	uv_mutex_destroy(&m_submitAuxBlockDataLock);
 
+	uv_mutex_destroy(&m_missingHeightsLock);
+
 	delete m_api;
 	delete m_sideChain;
 	delete m_hasher;
@@ -497,31 +508,64 @@ void p2pool::handle_miner_data(MinerData& data)
 			missing_heights.erase(std::unique(missing_heights.begin(), missing_heights.end()), missing_heights.end());
 		}
 
-		for (uint64_t h : missing_heights) {
-			LOGWARN(3, "Mainchain data for height " << h << " is missing, requesting it from monerod again");
+		MutexLock lock(m_missingHeightsLock);
+		m_missingHeights = std::move(missing_heights);
 
-			char buf[log::Stream::BUF_SIZE + 1] = {};
-			log::Stream s(buf);
-			s << "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_block_header_by_height\",\"params\":{\"height\":" << h << "}}\0";
-
-			JSONRPCRequest::call(host.m_address, host.m_rpcPort, buf, host.m_rpcLogin, m_params->m_socks5Proxy, host.m_rpcSSL, host.m_rpcSSL_Fingerprint,
-				[this, h](const char* data, size_t size, double)
-				{
-					ChainMain block;
-					if (!parse_block_header(data, size, block)) {
-						LOGERR(1, "couldn't download block header for height " << h);
-					}
-				},
-				[h](const char* data, size_t size, double)
-				{
-					if (size > 0) {
-						LOGERR(1, "couldn't download block header for height " << h << ", error " << log::const_buf(data, size));
-					}
-				});
+		if (!m_missingHeights.empty()) {
+			const int err = uv_async_send(&m_getMissingHeightsAsync);
+			if (err) {
+				LOGERR(1, "uv_async_send failed, error " << uv_err_name(err));
+			}
 		}
 	}
 }
 
+void p2pool::get_missing_heights()
+{
+	uint64_t h;
+	{
+		MutexLock lock(m_missingHeightsLock);
+
+		if (m_missingHeights.empty()) {
+			return;
+		}
+
+		h = m_missingHeights.back();
+		m_missingHeights.pop_back();
+	}
+
+	LOGWARN(3, "Mainchain data for height " << h << " is missing, requesting it from monerod again");
+
+	char buf[log::Stream::BUF_SIZE + 1] = {};
+	log::Stream s(buf);
+	s << "{\"jsonrpc\":\"2.0\",\"id\":\"0\",\"method\":\"get_block_header_by_height\",\"params\":{\"height\":" << h << "}}\0";
+
+	const Params::Host& host = current_host();
+
+	JSONRPCRequest::call(host.m_address, host.m_rpcPort, buf, host.m_rpcLogin, m_params->m_socks5Proxy, host.m_rpcSSL, host.m_rpcSSL_Fingerprint,
+		[this, h](const char* data, size_t size, double)
+		{
+			ChainMain block;
+			if (!parse_block_header(data, size, block)) {
+				LOGERR(1, "couldn't download block header for height " << h);
+
+				MutexLock lock(m_missingHeightsLock);
+				m_missingHeights.push_back(h);
+			}
+			get_missing_heights();
+		},
+		[this, h](const char* data, size_t size, double)
+		{
+			if (size > 0) {
+				LOGERR(1, "couldn't download block header for height " << h << ", error " << log::const_buf(data, size));
+
+				MutexLock lock(m_missingHeightsLock);
+				m_missingHeights.push_back(h);
+			}
+			get_missing_heights();
+		});
+}
+
 const char* BLOCK_FOUND = "\n\
 -----------------------------------------------------------------------------------------------\n\
 | ######   #        #######   #####   #    #      #######  #######  #     #  #     #  ######  |\n\
@@ -992,6 +1036,7 @@ void p2pool::on_stop(uv_async_t* async)
 	uv_close(reinterpret_cast<uv_handle_t*>(&pool->m_blockTemplateAsync), nullptr);
 	uv_close(reinterpret_cast<uv_handle_t*>(&pool->m_stopAsync), nullptr);
 	uv_close(reinterpret_cast<uv_handle_t*>(&pool->m_reconnectToHostAsync), nullptr);
+	uv_close(reinterpret_cast<uv_handle_t*>(&pool->m_getMissingHeightsAsync), nullptr);
 
 	init_signals(pool, false);
 
diff --git a/src/p2pool.h b/src/p2pool.h
index 048d8b4..5a5a763 100644
--- a/src/p2pool.h
+++ b/src/p2pool.h
@@ -151,6 +151,7 @@ private:
 	static void on_update_block_template(uv_async_t* async) { reinterpret_cast<p2pool*>(async->data)->update_block_template(); }
 	static void on_stop(uv_async_t*);
 	static void on_reconnect_to_host(uv_async_t* async) { reinterpret_cast<p2pool*>(async->data)->reconnect_to_host(); }
+	static void on_get_missing_heights(uv_async_t* async) { reinterpret_cast<p2pool*>(async->data)->get_missing_heights(); }
 
 	void submit_block() const;
 	void submit_aux_block() const;
@@ -261,6 +262,13 @@ private:
 	uint64_t m_startTime;
 	uv_async_t m_reconnectToHostAsync;
 
+	uv_async_t m_getMissingHeightsAsync;
+
+	mutable uv_mutex_t m_missingHeightsLock;
+	mutable std::vector<uint64_t> m_missingHeights;
+
+	void get_missing_heights();
+
 #ifndef P2POOL_UNIT_TESTS
 	mutable uv_rwlock_t m_ZMQReaderLock;
 	ZMQReader* m_ZMQReader = nullptr;