diff --git a/lib/tiny-cloud/init-final b/lib/tiny-cloud/init-final
index 1b50934..77d2f02 100644
--- a/lib/tiny-cloud/init-final
+++ b/lib/tiny-cloud/init-final
@@ -3,11 +3,6 @@
 
 source /lib/tiny-cloud/init-common
 
-match_header() {
-    local bytes=$(echo -en "$1")
-    [ "$bytes" = "$(dd bs=1 count=${#bytes} if="$2" 2>/dev/null)" ]
-}
-
 is_userdata_script() {
     head -n1 "$TINY_CLOUD_VAR/user-data" | grep -q "#!/"
 }
diff --git a/lib/tiny-cloud/init-main b/lib/tiny-cloud/init-main
index 26300e4..55ae0be 100644
--- a/lib/tiny-cloud/init-main
+++ b/lib/tiny-cloud/init-main
@@ -38,6 +38,11 @@ set_ssh_keys() {
     imds @ssh-keys > "$keys_file"
 }
 
+match_header() {
+    local bytes=$(echo -en "$1")
+    [ "$bytes" = "$(dd bs=1 count=${#bytes} if="$2" 2>/dev/null)" ]
+}
+
 save_userdata() {
     skip_action save_userdata && return
 
diff --git a/sbin/imds-net-sync b/sbin/imds-net-sync
index 00b220c..233a053 100755
--- a/sbin/imds-net-sync
+++ b/sbin/imds-net-sync
@@ -7,7 +7,7 @@
 
 source /lib/tiny-cloud/common
 
-[ "${IFACE:=unknown}" = unknown ] && log -s crit "IFACE not set, aborting"
+[ -z "${IFACE}" ] && log -s crit "IFACE not set, aborting"
 
 # kill interface's imds-net-sync daemon
 [ "$1" = '-k' ] && PHASE=pre-down && shift