diff --git a/Adafruit_I2CDevice.cpp b/Adafruit_I2CDevice.cpp
index 1b218d3..eeb863c 100644
--- a/Adafruit_I2CDevice.cpp
+++ b/Adafruit_I2CDevice.cpp
@@ -1,7 +1,7 @@
 #include <Adafruit_I2CDevice.h>
 #include <Arduino.h>
 
-#define DEBUG_SERIAL Serial
+//#define DEBUG_SERIAL Serial
 
 /*!
  *    @brief  Create an I2C device at a given address
diff --git a/Adafruit_SPIDevice.cpp b/Adafruit_SPIDevice.cpp
index 8f246f7..70ac411 100644
--- a/Adafruit_SPIDevice.cpp
+++ b/Adafruit_SPIDevice.cpp
@@ -1,7 +1,7 @@
 #include <Adafruit_SPIDevice.h>
 #include <Arduino.h>
 
-#define DEBUG_SERIAL Serial
+//#define DEBUG_SERIAL Serial
 
 /*!
  *    @brief  Create an SPI device with the given CS pin and settins