diff --git a/esphome/components/async_tcp/__init__.py b/esphome/components/async_tcp/__init__.py
index b07db9ed7c..c6c0a9de4d 100644
--- a/esphome/components/async_tcp/__init__.py
+++ b/esphome/components/async_tcp/__init__.py
@@ -9,7 +9,7 @@ CODEOWNERS = ["@OttoWinter"]
 def to_code(config):
     if CORE.is_esp32:
         # https://github.com/OttoWinter/AsyncTCP/blob/master/library.json
-        cg.add_library("AsyncTCP-esphome", "1.1.1")
+        cg.add_library("AsyncTCP-esphome", "1.2.1")
     elif CORE.is_esp8266:
         # https://github.com/OttoWinter/ESPAsyncTCP
         cg.add_library("ESPAsyncTCP-esphome", "1.2.3")
diff --git a/platformio.ini b/platformio.ini
index 1dbc88cfde..e9fedb0a1e 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -10,7 +10,7 @@ include_dir = include
 
 [common]
 lib_deps =
-    AsyncTCP-esphome@1.1.1
+    AsyncTCP-esphome@1.2.1
     AsyncMqttClient-esphome@0.8.4
     ArduinoJson-esphomelib@5.13.3
     ESPAsyncWebServer-esphome@1.2.7