diff --git a/ros_arduino_firmware/src/libraries/ROSArduinoBridge/encoder_driver.ino b/ros_arduino_firmware/src/libraries/ROSArduinoBridge/encoder_driver.ino
index e1792bb..85d401d 100644
--- a/ros_arduino_firmware/src/libraries/ROSArduinoBridge/encoder_driver.ino
+++ b/ros_arduino_firmware/src/libraries/ROSArduinoBridge/encoder_driver.ino
@@ -1,7 +1,7 @@
 /* *************************************************************
    Encoder definitions
    
-   Add a "#if defined" block to this file to include support for
+   Add an "#ifdef" block to this file to include support for
    a particular encoder board or library. Then add the appropriate
    #define near the top of the main ROSArduinoBridge.ino file.
    
@@ -27,7 +27,7 @@
     if (i == LEFT) return encoders.YAxisReset();
     else return encoders.XAxisReset();
   }
-#elif defined ARDUINO_ENC_COUNTER
+#elif ARDUINO_ENC_COUNTER
   volatile long left_enc_pos = 0L;
   volatile long right_enc_pos = 0L;
   static const int8_t ENC_STATES [] = {0,1,-1,0,-1,0,0,1,1,0,0,-1,0,-1,1,0};  //encoder lookup table