diff --git a/hosts b/hosts
index b293495..00c65a0 100755
--- a/hosts
+++ b/hosts
@@ -62,7 +62,7 @@ HOSTS_PATH="${HOSTS_PATH:-/etc/hosts}"
 # variable has been set. The command is expected to print a message and
 # should typically be either `echo`, `printf`, or `cat`.
 _debug() {
-  if [[ "${_use_debug:-"0"}" -eq 1 ]]
+  if [[ "${_USE_DEBUG:-"0"}" -eq 1 ]]
   then
     # Prefix debug message with "bug (U+1F41B)"
     printf "🐛  "