diff --git a/Particle/PCA9536_R21.ino b/Particle/PCA9536_R21.ino
index f8e2de4..9c90441 100755
--- a/Particle/PCA9536_R21.ino
+++ b/Particle/PCA9536_R21.ino
@@ -14,19 +14,22 @@ void setup()
 {
   // Set variable
   Particle.variable("i2cdevice", "PCA9536_R21");
-  
-  // Initialise I2C communication
-  Wire.begin();
   // Initialise Serial Communication, set baud rate = 9600
   Serial.begin(9600);
+  // Initialise I²C communication
+  Wire.begin();
+
+  // Turn off all channels prior to initialization of chip so relays do not turn on after initializing channels to outputs.
+  Wire.beginTransmission(Addr);
+  Wire.write(0x01);
+  Wire.write(0x00);
+  Wire.endTransmission();
 
-  // Start I2C transmission
   Wire.beginTransmission(Addr);
   // Select configuration register
   Wire.write(0x03);
   // Set all pins as OUTPUT
   Wire.write(0x00);
-  // Stop I2C transmission
   Wire.endTransmission();
   delay(300);
 }