diff --git a/libraries/esp8266/examples/ConfigFile/ConfigFile.ino b/libraries/esp8266/examples/ConfigFile/ConfigFile.ino
index 3503a10b5..77bbfabaa 100644
--- a/libraries/esp8266/examples/ConfigFile/ConfigFile.ino
+++ b/libraries/esp8266/examples/ConfigFile/ConfigFile.ino
@@ -31,16 +31,15 @@ bool loadConfig() {
   // use configFile.readString instead.
   configFile.readBytes(buf.get(), size);
 
-  StaticJsonBuffer<200> jsonBuffer;
-  JsonObject& json = jsonBuffer.parseObject(buf.get());
-
-  if (!json.success()) {
+  StaticJsonDocument<200> doc;
+  auto error = deserializeJson(doc, buf.get());
+  if (error) {
     Serial.println("Failed to parse config file");
     return false;
   }
 
-  const char* serverName = json["serverName"];
-  const char* accessToken = json["accessToken"];
+  const char* serverName = doc["serverName"];
+  const char* accessToken = doc["accessToken"];
 
   // Real world application would store these values in some variables for
   // later use.
@@ -53,10 +52,9 @@ bool loadConfig() {
 }
 
 bool saveConfig() {
-  StaticJsonBuffer<200> jsonBuffer;
-  JsonObject& json = jsonBuffer.createObject();
-  json["serverName"] = "api.example.com";
-  json["accessToken"] = "128du9as8du12eoue8da98h123ueh9h98";
+  StaticJsonDocument<200> doc;
+  doc["serverName"] = "api.example.com";
+  doc["accessToken"] = "128du9as8du12eoue8da98h123ueh9h98";
 
   File configFile = SPIFFS.open("/config.json", "w");
   if (!configFile) {
@@ -64,7 +62,7 @@ bool saveConfig() {
     return false;
   }
 
-  json.printTo(configFile);
+  serializeJson(doc, configFile);
   return true;
 }
 
diff --git a/tests/common.sh b/tests/common.sh
index 3d2a107d5..ca2c53523 100755
--- a/tests/common.sh
+++ b/tests/common.sh
@@ -135,7 +135,7 @@ function install_libraries()
     pushd $HOME/Arduino/libraries
 
     # install ArduinoJson library
-    { test -r ArduinoJson-v4.6.1.zip || wget https://github.com/bblanchon/ArduinoJson/releases/download/v4.6.1/ArduinoJson-v4.6.1.zip; } && unzip ArduinoJson-v4.6.1.zip
+    { test -r ArduinoJson-v6.11.0.zip || wget https://github.com/bblanchon/ArduinoJson/releases/download/v6.11.0/ArduinoJson-v6.11.0.zip; } && unzip ArduinoJson-v6.11.0.zip
 
     popd
 }
diff --git a/tests/platformio.sh b/tests/platformio.sh
index c6db433fb..bacd1704e 100755
--- a/tests/platformio.sh
+++ b/tests/platformio.sh
@@ -12,7 +12,7 @@ function install_platformio()
     ln -s $TRAVIS_BUILD_DIR ~/.platformio/packages/framework-arduinoespressif8266
     # Install dependencies:
     # - esp8266/examples/ConfigFile
-    pio lib install "ArduinoJson@^5.13.4"
+    pio lib install "ArduinoJson@^6.11.0"
 }
 
 function build_sketches_with_platformio()