diff --git a/Dockerfile b/Dockerfile
index b4d1a043..b9b7d065 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -33,6 +33,9 @@ RUN pip install --no-cache-dir poetry && \
 
 FROM base
 
+# Install gcc so packages installed durring runtime may be build
+RUN apt-get update && apt-get install -y gcc && gcc --version
+
 RUN useradd -m -s /bin/bash mqtt_io
 USER mqtt_io
 WORKDIR /home/mqtt_io
@@ -43,5 +46,6 @@ RUN venv/bin/python -m pip install --no-cache-dir --upgrade pip
 RUN venv/bin/pip install --no-cache-dir -r requirements.txt
 
 COPY --chown=mqtt_io mqtt_io mqtt_io
+RUN gcc --version
 
 CMD [ "venv/bin/python", "-m", "mqtt_io", "/config.yml" ]
diff --git a/README.md b/README.md
index b092319e..81f2dcbc 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,7 @@ Hardware support is provided by specific GPIO, Sensor and Stream modules. It's e
   - ADXl345 3-axis accelerometer up to ±16g  (`adxl345`)
   - PMS5003 particulate sensor (`pms5003`)
   - SHT40/SHT41/SHT45 temperature and humidity sensors (`sht4x`)
+  - YF-S201 flow rate sensor (`yfs201`)
 
 ### Streams
 
diff --git a/mqtt_io/modules/sensor/bmp085.py b/mqtt_io/modules/sensor/bmp085.py
index c8ba91ed..768f5791 100644
--- a/mqtt_io/modules/sensor/bmp085.py
+++ b/mqtt_io/modules/sensor/bmp085.py
@@ -36,7 +36,7 @@ class Sensor(GenericSensor):
     def setup_module(self) -> None:
         # pylint: disable=import-outside-toplevel,attribute-defined-outside-init
         # pylint: disable=import-error,no-member
-        from Adafruit_BMP.BMP085 import BMP085
+        from Adafruit_BMP.BMP085 import BMP085 # type: ignore
 
         self.address: int = self.config["chip_addr"]
         self.bmp = BMP085(address=self.address)
@@ -46,6 +46,6 @@ def get_value(self, sens_conf: ConfigType) -> SensorValueType:
         Get the temperature, humidity or pressure value from the sensor
         """
         sens_type = sens_conf["type"]
-        data = DATA_READER[sens_type](self.bmp)
+        #error: Call to untyped function (unknown) in typed context
+        data = DATA_READER[sens_type](self.bmp) # type: ignore
         return cast(float, data)
-
diff --git a/mqtt_io/modules/sensor/dht22.py b/mqtt_io/modules/sensor/dht22.py
index 48aaf3f5..49bfaba9 100644
--- a/mqtt_io/modules/sensor/dht22.py
+++ b/mqtt_io/modules/sensor/dht22.py
@@ -37,7 +37,7 @@ class Sensor(GenericSensor):
     def setup_module(self) -> None:
         # pylint: disable=import-outside-toplevel,import-error
         import adafruit_dht  # type: ignore
-        from microcontroller import Pin
+        from microcontroller import Pin # type: ignore
 
         sensor_type: str = self.config["type"].lower()
 
diff --git a/mqtt_io/modules/sensor/yfs201.py b/mqtt_io/modules/sensor/yfs201.py
new file mode 100644
index 00000000..6fc3fcc0
--- /dev/null
+++ b/mqtt_io/modules/sensor/yfs201.py
@@ -0,0 +1,94 @@
+"""
+
+YF-S201 Flow Rate Sensor
+
+Example configuration:
+
+sensor_modules:
+  - name: yfs201
+    module: yfs201
+
+sensor_inputs:
+  - name: flow_rate1
+    module: yfs201
+    pin: 0
+    digits: 0
+    interval: 10
+"""
+
+from typing import Dict
+from ...types import CerberusSchemaType, ConfigType, SensorValueType
+from . import GenericSensor
+
+REQUIREMENTS = ("gpiozero",)
+
+
+class YFS201:
+    """
+    YF-S201 Flow Rate Sensor class
+    Multiple instances support multiple sensors on different pins
+    """
+
+    def __init__(self, gpiozero, name: str, pin: int) -> None: # type: ignore[no-untyped-def]
+        self.name = name
+        self.pin = gpiozero.DigitalInputDevice(pin)
+        self.pin.when_activated = self.count_pulse
+        self.count = 0
+
+    def count_pulse(self) -> None:
+        """Increment pulse count."""
+        self.count += 1
+
+    def reset_count(self) -> None:
+        """Reset pulse count."""
+        self.count = 0
+
+    def flow_rate(self, sample_window: int) -> float:
+        """Return flow rate in liters per minute.
+
+        From YF-S201 manual:
+        Pluse Characteristic:F=7Q(L/MIN).
+        2L/MIN=16HZ 4L/MIN=32.5HZ 6L/MIN=49.3HZ 8L/MIN=65.5HZ 10L/MIN=82HZ
+
+        Pulse frequency (Hz) / 7.0 = flow rate in L/min
+
+        sample_window is in seconds, so hz is pulse_count / sample_window
+        """
+        hertz = self.count / sample_window
+        return hertz / 7.0
+
+    def get_value(self, interval: int) -> float:
+        """Return flow rate in L/min over interval seconds and reset count."""
+        flow_rate = self.flow_rate(interval)
+        self.reset_count()
+        return flow_rate
+
+
+class Sensor(GenericSensor):
+    """
+    YF-S201 Flow Rate Sensor
+    """
+
+    SENSOR_SCHEMA: CerberusSchemaType = {
+        "pin": dict(
+            type="integer",
+            required=True,
+            empty=False,
+        )
+    }
+
+    def setup_module(self) -> None:
+        # pylint: disable=import-outside-toplevel,import-error
+        import gpiozero  # type: ignore
+
+        self.gpiozero = gpiozero
+        self.sensors: Dict[str, YFS201] = {}
+
+    def setup_sensor(self, sens_conf: ConfigType) -> None:
+        sensor = YFS201(
+            gpiozero=self.gpiozero, name=sens_conf["name"], pin=sens_conf["pin"]
+        )
+        self.sensors[sensor.name] = sensor
+
+    def get_value(self, sens_conf: ConfigType) -> SensorValueType:
+        return self.sensors[sens_conf["name"]].get_value(sens_conf["interval"])