diff --git a/libraries/WiFiClientSecure/src/ssl_client.cpp b/libraries/WiFiClientSecure/src/ssl_client.cpp
index efe0a449..12a52b35 100644
--- a/libraries/WiFiClientSecure/src/ssl_client.cpp
+++ b/libraries/WiFiClientSecure/src/ssl_client.cpp
@@ -290,7 +290,7 @@ int data_to_read(sslclient_context *ssl_client)
     return res;
 }
 
-int send_ssl_data(sslclient_context *ssl_client, const uint8_t *data, uint16_t len)
+int send_ssl_data(sslclient_context *ssl_client, const uint8_t *data, size_t len)
 {
     log_v("Writing HTTP request with %d bytes...", len); //for low level debug
     int ret = -1;
diff --git a/libraries/WiFiClientSecure/src/ssl_client.h b/libraries/WiFiClientSecure/src/ssl_client.h
index 33a5e488..5ee662fb 100644
--- a/libraries/WiFiClientSecure/src/ssl_client.h
+++ b/libraries/WiFiClientSecure/src/ssl_client.h
@@ -32,7 +32,7 @@ void ssl_init(sslclient_context *ssl_client);
 int start_ssl_client(sslclient_context *ssl_client, const char *host, uint32_t port, int timeout, const char *rootCABuff, const char *cli_cert, const char *cli_key, const char *pskIdent, const char *psKey, bool insecure);
 void stop_ssl_socket(sslclient_context *ssl_client, const char *rootCABuff, const char *cli_cert, const char *cli_key);
 int data_to_read(sslclient_context *ssl_client);
-int send_ssl_data(sslclient_context *ssl_client, const uint8_t *data, uint16_t len);
+int send_ssl_data(sslclient_context *ssl_client, const uint8_t *data, size_t len);
 int get_ssl_receive(sslclient_context *ssl_client, uint8_t *data, int length);
 bool verify_ssl_fingerprint(sslclient_context *ssl_client, const char* fp, const char* domain_name);
 bool verify_ssl_dn(sslclient_context *ssl_client, const char* domain_name);