diff --git a/repositories.txt b/repositories.txt
index 5f7c9c06..4449a23c 100644
--- a/repositories.txt
+++ b/repositories.txt
@@ -1,4 +1,5 @@
 https://github.com/X-croot/BuzzerXCR
+https://github.com/X-croot/MQ135-XCR
 https://github.com/AbdulKus/72x40oled_lib
 https://github.com/X-croot/UltraSonicXCR
 https://github.com/X-croot/RelayXCR