diff --git a/config.mk b/config.mk
index 3141d2107264408ee96df1436eae9656cc537f79..cf423522c78e8707de630cefd03b1c350d7efb5f 100644
--- a/config.mk
+++ b/config.mk
@@ -22,7 +22,7 @@ xinerama_ld = -lXinerama
 
 debug = -DDEBUG
 # Uncomment this for debug mode
-# (Use feh -+ <level> to see debug output)
+# (Use feh -+ <level> or feh --debug-level <level> to see debug output)
 #CFLAGS += ${debug}
 
 dmalloc = -DWITH_DMALLOC