diff --git a/lib/dns.py b/lib/dns.py
index 8d09d53..c56d4f7 100644
--- a/lib/dns.py
+++ b/lib/dns.py
@@ -6,8 +6,6 @@
 PROCESS_IPv6 = True
 
 # paths are set in util (shared between addons)
-APPENDIX_4 = '_v4'
-APPENDIX_6 = '_v6'
 CONFIG_FILE = 'dns.json'
 CONFIG_FILE_KEY = 'dns'
 OUT_FILE = 'dns.nft'
@@ -34,7 +32,6 @@
     lines.append(
         format_var(
             name=var,
-            append=APPENDIX_4,
             data=values_v4,
             version=4,
         )
@@ -44,7 +41,6 @@
         lines.append(
             format_var(
                 name=var,
-                append=APPENDIX_6,
                 data=values_v6,
                 version=6,
             )
diff --git a/lib/util.py b/lib/util.py
index 2b38c30..375b29e 100644
--- a/lib/util.py
+++ b/lib/util.py
@@ -14,6 +14,8 @@
 BASE_DIR = '/etc/nftables.d'
 ADDON_DIR = '/etc/nftables.d/addons'
 CONFIG_EXT = 'nft'
+APPENDIX_4 = '_v4'
+APPENDIX_6 = '_v6'
 
 if not CONFIG_EXT.startswith('.'):
     CONFIG_EXT = f'.{CONFIG_EXT}'
@@ -26,10 +28,12 @@
 FILE_HEADER = '# Auto-Generated config - DO NOT EDIT MANUALLY!\n\n'
 
 
-def format_var(name: str, data: list, version: int, append: str = None) -> str:
+def format_var(name: str, data: list, version: int) -> str:
     if version not in FALLBACK_VAR_VALUE:
         version = 4
 
+    append = APPENDIX_4 if version == 4 else APPENDIX_6
+
     if append not in [None, ' ', '']:
         name = f'{name}_{append}'