diff --git a/psu b/psu
index cf56cf7..4e95999 100644
--- a/psu
+++ b/psu
@@ -5,6 +5,7 @@
 # And more!
 
 set -e
+[[ "$PSU_TRACE" ]] && set -x
 
 ############################
 # Main entrypoint          #