diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 94116bcee1..accc647c28 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -41,11 +41,11 @@ stages:
 
     - |
       if [[ "${IS_HASSIO}" == "YES" ]]; then
-        BUILD_FROM=esphome/esphome-hassio-base-${BUILD_ARCH}:1.5.1
+        BUILD_FROM=esphome/esphome-hassio-base-${BUILD_ARCH}:1.6.0
         BUILD_TO=esphome/esphome-hassio-${BUILD_ARCH}
         DOCKERFILE=docker/Dockerfile.hassio
       else
-        BUILD_FROM=esphome/esphome-base-${BUILD_ARCH}:1.5.1
+        BUILD_FROM=esphome/esphome-base-${BUILD_ARCH}:1.6.0
         if [[ "${BUILD_ARCH}" == "amd64" ]]; then
           BUILD_TO=esphome/esphome
         else
diff --git a/docker/Dockerfile b/docker/Dockerfile
index f844fa741e..f70d3e35a5 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,4 +1,4 @@
-ARG BUILD_FROM=esphome/esphome-base-amd64:1.5.1
+ARG BUILD_FROM=esphome/esphome-base-amd64:1.6.0
 FROM ${BUILD_FROM}
 
 COPY . .
diff --git a/esphome/automation.py b/esphome/automation.py
index d6d568f7ef..07c3b0177f 100644
--- a/esphome/automation.py
+++ b/esphome/automation.py
@@ -128,7 +128,7 @@ def or_condition_to_code(config, condition_id, template_arg, args):
     yield cg.new_Pvariable(condition_id, template_arg, conditions)
 
 
-@register_condition('not', NotCondition, validate_condition)
+@register_condition('not', NotCondition, validate_potentially_and_condition)
 def not_condition_to_code(config, condition_id, template_arg, args):
     condition = yield build_condition(config, template_arg, args)
     yield cg.new_Pvariable(condition_id, template_arg, condition)
diff --git a/esphome/components/logger/__init__.py b/esphome/components/logger/__init__.py
index 27141f93c2..94b33ae18e 100644
--- a/esphome/components/logger/__init__.py
+++ b/esphome/components/logger/__init__.py
@@ -112,7 +112,7 @@ def to_code(config):
 
     if CORE.is_esp8266 and has_serial_logging and is_at_least_verbose:
         debug_serial_port = HARDWARE_UART_TO_SERIAL[config.get(CONF_HARDWARE_UART)]
-        cg.add_build_flag("-DDEBUG_ESP_PORT{}".format(debug_serial_port))
+        cg.add_build_flag("-DDEBUG_ESP_PORT={}".format(debug_serial_port))
         cg.add_build_flag("-DLWIP_DEBUG")
         DEBUG_COMPONENTS = {
             'HTTP_CLIENT',
diff --git a/esphome/const.py b/esphome/const.py
index 5ee9d60c98..d58ed406c7 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -18,6 +18,7 @@ ARDUINO_VERSION_ESP32_1_0_1 = 'espressif32@1.6.0'
 ARDUINO_VERSION_ESP8266_DEV = 'https://github.com/platformio/platform-espressif8266.git#feature' \
                               '/stage'
 ARDUINO_VERSION_ESP8266_2_5_0 = 'espressif8266@2.0.0'
+ARDUINO_VERSION_ESP8266_2_5_1 = 'espressif8266@2.1.0'
 ARDUINO_VERSION_ESP8266_2_3_0 = 'espressif8266@1.5.0'
 SOURCE_FILE_EXTENSIONS = {'.cpp', '.hpp', '.h', '.c', '.tcc', '.ino'}
 HEADER_FILE_EXTENSIONS = {'.h', '.hpp', '.tcc'}
diff --git a/esphome/core_config.py b/esphome/core_config.py
index 3ed07a8343..71942c05e0 100644
--- a/esphome/core_config.py
+++ b/esphome/core_config.py
@@ -11,7 +11,7 @@ from esphome.const import ARDUINO_VERSION_ESP32_DEV, ARDUINO_VERSION_ESP8266_DEV
     CONF_NAME, CONF_ON_BOOT, CONF_ON_LOOP, CONF_ON_SHUTDOWN, CONF_PLATFORM, \
     CONF_PLATFORMIO_OPTIONS, CONF_PRIORITY, CONF_TRIGGER_ID, \
     CONF_ESP8266_RESTORE_FROM_FLASH, __version__, ARDUINO_VERSION_ESP8266_2_3_0, \
-    ARDUINO_VERSION_ESP8266_2_5_0
+    ARDUINO_VERSION_ESP8266_2_5_0, ARDUINO_VERSION_ESP8266_2_5_1
 from esphome.core import CORE, coroutine_with_priority
 from esphome.pins import ESP8266_FLASH_SIZES, ESP8266_LD_SCRIPTS
 
@@ -42,12 +42,13 @@ def validate_board(value):
 validate_platform = cv.one_of('ESP32', 'ESP8266', upper=True)
 
 PLATFORMIO_ESP8266_LUT = {
+    '2.5.1': 'espressif8266@2.1.0',
     '2.5.0': 'espressif8266@2.0.1',
     '2.4.2': 'espressif8266@1.8.0',
     '2.4.1': 'espressif8266@1.7.3',
     '2.4.0': 'espressif8266@1.6.0',
     '2.3.0': 'espressif8266@1.5.0',
-    'RECOMMENDED': 'espressif8266@1.8.0',
+    'RECOMMENDED': 'espressif8266@2.1.0',
     'LATEST': 'espressif8266',
     'DEV': ARDUINO_VERSION_ESP8266_DEV,
 }
@@ -189,15 +190,14 @@ def to_code(config):
         if CORE.arduino_version in ('espressif8266@1.8.0', 'espressif8266@1.7.3',
                                     'espressif8266@1.6.0'):
             ld_script = ld_scripts[0]
-        elif CORE.arduino_version in (ARDUINO_VERSION_ESP8266_DEV, ARDUINO_VERSION_ESP8266_2_5_0):
+        elif CORE.arduino_version in (ARDUINO_VERSION_ESP8266_DEV, ARDUINO_VERSION_ESP8266_2_5_0,
+                                      ARDUINO_VERSION_ESP8266_2_5_1):
             ld_script = ld_scripts[1]
 
         if ld_script is not None:
             cg.add_build_flag('-Wl,-T{}'.format(ld_script))
 
-    if CORE.is_esp8266 and CORE.arduino_version in (ARDUINO_VERSION_ESP8266_DEV,
-                                                    ARDUINO_VERSION_ESP8266_2_5_0):
-        cg.add_build_flag('-fno-exceptions')
+    cg.add_build_flag('-fno-exceptions')
 
     # Libraries
     if CORE.is_esp32: