diff --git a/src/base/net/stratum/Client.cpp b/src/base/net/stratum/Client.cpp
index f9c56e05..ab493585 100644
--- a/src/base/net/stratum/Client.cpp
+++ b/src/base/net/stratum/Client.cpp
@@ -79,7 +79,8 @@ static const char *states[] = {
 
 xmrig::Client::Client(int id, const char *agent, IClientListener *listener) :
     BaseClient(id, listener),
-    m_agent(agent)
+    m_agent(agent),
+    m_sendBuf(1024)
 {
     m_key = m_storage.add(this);
     m_dns = new Dns(this);
@@ -158,13 +159,11 @@ int64_t xmrig::Client::send(const rapidjson::Value &obj)
     obj.Accept(writer);
 
     const size_t size = buffer.GetSize();
-    if (size > (sizeof(m_sendBuf) - 2)) {
-        LOG_ERR("[%s] send failed: \"send buffer overflow: %zu > %zu\"", url(), size, (sizeof(m_sendBuf) - 2));
-        close();
-        return -1;
+    if (size > (m_sendBuf.size() - 2)) {
+        m_sendBuf.resize(((size + 1) / 1024 + 1) * 1024);
     }
 
-    memcpy(m_sendBuf, buffer.GetString(), size);
+    memcpy(m_sendBuf.data(), buffer.GetString(), size);
     m_sendBuf[size]     = '\n';
     m_sendBuf[size + 1] = '\0';
 
@@ -186,8 +185,8 @@ int64_t xmrig::Client::submit(const JobResult &result)
     const char *nonce = result.nonce;
     const char *data  = result.result;
 #   else
-    char *nonce = m_sendBuf;
-    char *data  = m_sendBuf + 16;
+    char *nonce = m_sendBuf.data();
+    char *data  = m_sendBuf.data() + 16;
 
     Buffer::toHex(reinterpret_cast<const char*>(&result.nonce), 4, nonce);
     nonce[8] = '\0';
@@ -529,11 +528,11 @@ int xmrig::Client::resolve(const String &host)
 
 int64_t xmrig::Client::send(size_t size)
 {
-    LOG_DEBUG("[%s] send (%d bytes): \"%.*s\"", url(), size, static_cast<int>(size) - 1, m_sendBuf);
+    LOG_DEBUG("[%s] send (%d bytes): \"%.*s\"", url(), size, static_cast<int>(size) - 1, m_sendBuf.data());
 
 #   ifdef XMRIG_FEATURE_TLS
     if (isTLS()) {
-        if (!m_tls->send(m_sendBuf, size)) {
+        if (!m_tls->send(m_sendBuf.data(), size)) {
             return -1;
         }
     }
@@ -545,7 +544,7 @@ int64_t xmrig::Client::send(size_t size)
             return -1;
         }
 
-        uv_buf_t buf = uv_buf_init(m_sendBuf, (unsigned int) size);
+        uv_buf_t buf = uv_buf_init(m_sendBuf.data(), (unsigned int) size);
 
         if (uv_try_write(m_stream, &buf, 1) < 0) {
             close();
@@ -795,7 +794,7 @@ void xmrig::Client::parseResponse(int64_t id, const rapidjson::Value &result, co
 
 void xmrig::Client::ping()
 {
-    send(snprintf(m_sendBuf, sizeof(m_sendBuf), "{\"id\":%" PRId64 ",\"jsonrpc\":\"2.0\",\"method\":\"keepalived\",\"params\":{\"id\":\"%s\"}}\n", m_sequence, m_rpcId.data()));
+    send(snprintf(m_sendBuf.data(), m_sendBuf.size(), "{\"id\":%" PRId64 ",\"jsonrpc\":\"2.0\",\"method\":\"keepalived\",\"params\":{\"id\":\"%s\"}}\n", m_sequence, m_rpcId.data()));
 
     m_keepAlive = 0;
 }
diff --git a/src/base/net/stratum/Client.h b/src/base/net/stratum/Client.h
index fbf594a5..4db21219 100644
--- a/src/base/net/stratum/Client.h
+++ b/src/base/net/stratum/Client.h
@@ -128,11 +128,11 @@ private:
 
     static inline Client *getClient(void *data) { return m_storage.get(data); }
 
-    char m_sendBuf[4096] = { 0 };
     const char *m_agent;
     Dns *m_dns;
     RecvBuf<kInputBufferSize> m_recvBuf;
     std::bitset<EXT_MAX> m_extensions;
+    std::vector<char> m_sendBuf;
     String m_rpcId;
     Tls *m_tls                  = nullptr;
     uint64_t m_expire           = 0;