diff --git a/README.md b/README.md
index a8014dbd1..a347be7cb 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@ Arduino core for ESP8266 WiFi chip
 
 # Quick links
 
-- [Latest release documentation](https://arduino-esp8266.readthedocs.io/en/2.5.1/)
+- [Latest release documentation](https://arduino-esp8266.readthedocs.io/en/2.5.2/)
 - [Current "git version" documentation](https://arduino-esp8266.readthedocs.io/en/latest/)
 - [Install git version](https://arduino-esp8266.readthedocs.io/en/latest/installing.html#using-git-version) ([sources](doc/installing.rst#using-git-version))
 
@@ -36,7 +36,7 @@ Starting with 1.6.4, Arduino allows installation of third-party platform package
 #### Latest release [![Latest release](https://img.shields.io/github/release/esp8266/Arduino.svg)](https://github.com/esp8266/Arduino/releases/latest/)
 Boards manager link: `https://arduino.esp8266.com/stable/package_esp8266com_index.json`
 
-Documentation: [https://arduino-esp8266.readthedocs.io/en/2.5.1/](https://arduino-esp8266.readthedocs.io/en/2.5.1/)
+Documentation: [https://arduino-esp8266.readthedocs.io/en/2.5.2/](https://arduino-esp8266.readthedocs.io/en/2.5.2/)
 
 ### Using git version (basic instructions)
 [![Linux build status](https://travis-ci.org/esp8266/Arduino.svg)](https://travis-ci.org/esp8266/Arduino)
diff --git a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
index 7ae53e6b9..b71a5fa7b 100644
--- a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
+++ b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
@@ -248,6 +248,7 @@ void WiFiClientSecure::_freeSSL() {
   _recvapp_len = 0;
   // This connection is toast
   _handshake_done = false;
+  _timeout = 15000;
 }
 
 bool WiFiClientSecure::_clientConnected() {
@@ -1009,6 +1010,9 @@ bool WiFiClientSecure::_connectSSL(const char* hostName) {
   _x509_insecure = nullptr;
   _x509_knownkey = nullptr;
 
+  // reduce timeout after successful handshake to fail fast if server stop accepting our data for whathever reason
+  if (ret) _timeout = 5000;
+
   return ret;
 }
 
diff --git a/libraries/ESP8266WiFi/src/include/ClientContext.h b/libraries/ESP8266WiFi/src/include/ClientContext.h
index 0126621a6..2f2891510 100644
--- a/libraries/ESP8266WiFi/src/include/ClientContext.h
+++ b/libraries/ESP8266WiFi/src/include/ClientContext.h
@@ -456,7 +456,8 @@ protected:
             }
 
             _send_waiting = true;
-            esp_yield();
+            // This delay will be interrupted by esp_schedule on next received ack
+            delay(_timeout_ms);
         } while(true);
         _send_waiting = false;
 
diff --git a/tools/elf2bin.py b/tools/elf2bin.py
index 5d63c4fdb..214cd9407 100755
--- a/tools/elf2bin.py
+++ b/tools/elf2bin.py
@@ -25,7 +25,7 @@ import subprocess
 import sys
 import tempfile
 
-fmodeb = { 'dout': 3, 'dio': 2, 'quot': 1, 'qio': 0 }
+fmodeb = { 'dout': 3, 'dio': 2, 'qout': 1, 'qio': 0 }
 ffreqb = { '40': 0, '26': 1, '20': 2, '80': 15 }
 fsizeb = { '512K': 0, '256K': 1, '1M': 2, '2M': 3, '4M': 4, '8M': 8, '16M': 9 }
 
diff --git a/tools/platformio-build.py b/tools/platformio-build.py
index 18b44c2c2..ce5bbb2de 100644
--- a/tools/platformio-build.py
+++ b/tools/platformio-build.py
@@ -135,16 +135,16 @@ env.Append(
         ElfToBin=Builder(
             action=env.VerboseAction(" ".join([
                 '"$PYTHONEXE"',
-                '"%s"' % env.subst(join(FRAMEWORK_DIR, "tools", "elf2bin.py")),
-                "--eboot", '"%s"' % env.subst(join(
-                    FRAMEWORK_DIR, "bootloaders", "eboot", "eboot.elf")),
-                "--app", '"%s"' % "$SOURCE",
+                '"%s"' % join(FRAMEWORK_DIR, "tools", "elf2bin.py"),
+                "--eboot", '"%s"' % join(
+                    FRAMEWORK_DIR, "bootloaders", "eboot", "eboot.elf"),
+                "--app", "$SOURCE",
                 "--flash_mode", "$BOARD_FLASH_MODE",
                 "--flash_freq", "${__get_board_f_flash(__env__)}",
                 "--flash_size", "${__get_flash_size(__env__)}",
-                "--path", '"%s"' % env.subst(join(
-                    platform.get_package_dir("toolchain-xtensa"), "bin")),
-                "--out", '"$TARGET"'
+                "--path", '"%s"' % join(
+                    platform.get_package_dir("toolchain-xtensa"), "bin"),
+                "--out", "$TARGET"
             ]), "Building $TARGET"),
             suffix=".bin"
         )