diff --git a/esphome/components/api.py b/esphome/components/api.py
index 86e77bb4c6..544d0e418b 100644
--- a/esphome/components/api.py
+++ b/esphome/components/api.py
@@ -86,7 +86,7 @@ def lib_deps(config):
     if CORE.is_esp32:
         return 'AsyncTCP@1.0.3'
     if CORE.is_esp8266:
-        return 'ESPAsyncTCP@1.1.3'
+        return 'ESPAsyncTCP@1.2.0'
     raise NotImplementedError
 
 
diff --git a/esphome/writer.py b/esphome/writer.py
index 953680e467..9c2bc8fbd8 100644
--- a/esphome/writer.py
+++ b/esphome/writer.py
@@ -290,7 +290,7 @@ def gather_lib_deps():
             lib_deps.add('AsyncTCP@1.0.1')
         lib_deps.add('ESPmDNS')
     elif CORE.is_esp8266:
-        lib_deps.add('ESPAsyncTCP@1.1.3')
+        lib_deps.add('ESPAsyncTCP@1.2.0')
         lib_deps.add('ESP8266mDNS')
 
     # avoid changing build flags order