diff --git a/repositories.txt b/repositories.txt
index b1daf6f3..4e47d7f1 100644
--- a/repositories.txt
+++ b/repositories.txt
@@ -1,3 +1,4 @@
+https://github.com/Phoenix1747/MQ135
 https://github.com/BreadBoardMates/Arduino-Mates-Controller
 https://github.com/MajicDesigns/MD_Stepper
 https://github.com/DFRobot/DFRobot_BMP3XX