diff --git a/src/etc/inc/filter.inc b/src/etc/inc/filter.inc
index 12395a3e6..f942a5251 100644
--- a/src/etc/inc/filter.inc
+++ b/src/etc/inc/filter.inc
@@ -55,6 +55,34 @@ function is_bogonsv6_used()
     return $usebogonsv6;
 }
 
+/* lock configuration file */
+function filter_lock($lock = 'filter', $op = LOCK_EX)
+{
+    if (!$lock) {
+        die(gettext("WARNING: You must give a name as parameter to lock() function."));
+    }
+
+    if (!file_exists("{/tmp/{$lock}.lock")) {
+        @touch("/tmp/{$lock}.lock");
+        @chmod("/tmp/{$lock}.lock", 0666);
+    }
+
+    if ($fp = fopen("/tmp/{$lock}.lock", 'a+e')) {
+        if (flock($fp, $op)) {
+            return $fp;
+        } else {
+            fclose($fp);
+        }
+    }
+}
+
+/* unlock configuration file */
+function filter_unlock($fp)
+{
+    flock($fp, LOCK_UN);
+    fclose($fp);
+}
+
 /* sort by interface only, retain the original order of rules that apply to
    the same interface */
 function filter_rules_sort()
@@ -158,7 +186,7 @@ function filter_configure_sync($verbose = false, $load_aliases = true)
     service_log('Configuring firewall.', $verbose);
 
     /* Use filter lock to not allow concurrent filter reloads during this run. */
-    $filterlck = lock('filter', LOCK_EX);
+    $locked = filter_lock();
 
     ifgroup_setup();
 
@@ -273,7 +301,7 @@ function filter_configure_sync($verbose = false, $load_aliases = true)
     } else {
         mwexec("/sbin/pfctl -d", true);
 
-        unlock($filterlck);
+        filter_unlock($locked);
         closelog();
         reopenlog();
 
@@ -381,7 +409,7 @@ function filter_configure_sync($verbose = false, $load_aliases = true)
         syslog(LOG_ERR, 'ERROR: Could not write new rules!');
         file_put_contents('/tmp/rules.error', gettext('ERROR: Could not write new rules!'));
 
-        unlock($filterlck);
+        filter_unlock($locked);
         closelog();
         reopenlog();
 
@@ -423,7 +451,7 @@ function filter_configure_sync($verbose = false, $load_aliases = true)
             sprintf(gettext('There were error(s) loading the rules: %s%s'), $rules_error[0], $config_line)
         );
 
-        unlock($filterlck);
+        filter_unlock($locked);
         closelog();
         reopenlog();
 
@@ -457,7 +485,7 @@ function filter_configure_sync($verbose = false, $load_aliases = true)
     killbypid('/var/run/filterlog.pid');
     mwexec('/usr/local/sbin/filterlog -i pflog0 -p /var/run/filterlog.pid');
 
-    unlock($filterlck);
+    filter_unlock($locked);
     closelog();
     reopenlog();
 
diff --git a/src/etc/inc/util.inc b/src/etc/inc/util.inc
index c6c71052c..7a4d4bf19 100644
--- a/src/etc/inc/util.inc
+++ b/src/etc/inc/util.inc
@@ -306,34 +306,6 @@ function clear_subsystem_dirty($subsystem = '')
     @unlink("/tmp/{$subsystem}.dirty");
 }
 
-/* lock configuration file */
-function lock($lock, $op = LOCK_SH)
-{
-    if (!$lock) {
-        die(gettext("WARNING: You must give a name as parameter to lock() function."));
-    }
-
-    if (!file_exists("{/tmp/{$lock}.lock")) {
-        @touch("/tmp/{$lock}.lock");
-        @chmod("/tmp/{$lock}.lock", 0666);
-    }
-
-    if ($fp = fopen("/tmp/{$lock}.lock", 'a+e')) {
-        if (flock($fp, $op)) {
-            return $fp;
-        } else {
-            fclose($fp);
-        }
-    }
-}
-
-/* unlock configuration file */
-function unlock($fp)
-{
-    flock($fp, LOCK_UN);
-    fclose($fp);
-}
-
 function exit_on_bootup($callback = null, $arguments = [])
 {
     if (product::getInstance()->booting()) {