diff --git a/homeassistant/components/switch/acer_projector.py b/homeassistant/components/switch/acer_projector.py
index 5fb7fad909d..b0a6a93cb4d 100644
--- a/homeassistant/components/switch/acer_projector.py
+++ b/homeassistant/components/switch/acer_projector.py
@@ -27,7 +27,7 @@ CMD_DICT = {LAMP: '* 0 Lamp ?\r',
             STATE_OFF: '* 0 IR 002\r'}
 
 _LOGGER = logging.getLogger(__name__)
-REQUIREMENTS = ['pyserial<=3.0']
+REQUIREMENTS = ['pyserial<=3.1']
 
 ICON = 'mdi:projector'
 
diff --git a/requirements_all.txt b/requirements_all.txt
index ff8783a54b4..d65e3af8a82 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -303,7 +303,7 @@ pynx584==0.2
 pyowm==2.3.2
 
 # homeassistant.components.switch.acer_projector
-pyserial<=3.0
+pyserial<=3.1
 
 # homeassistant.components.device_tracker.snmp
 # homeassistant.components.sensor.snmp