diff --git a/books/beaglebone-cookbook/02sensors/sensors.rst b/books/beaglebone-cookbook/02sensors/sensors.rst
index 3a8ef0bf2f30f7a83ae4ad929a6881a289bc109b..877ec229e8dae13071ba6883d59aaddc33676d7f 100644
--- a/books/beaglebone-cookbook/02sensors/sensors.rst
+++ b/books/beaglebone-cookbook/02sensors/sensors.rst
@@ -5,6 +5,7 @@ Sensors
 
 .. |kohm| replace:: kΩ
 .. |ohm| replace:: Ω
+.. |deg| replace:: °
 
 In this chapter, you will learn how to sense the physical world with BeagleBone Black. 
 Various types of electronic sensors, such as cameras and microphones, can be connected