diff --git a/mktxp/collector/base_collector.py b/mktxp/collector/base_collector.py
index 8f84ea6..5e7db20 100644
--- a/mktxp/collector/base_collector.py
+++ b/mktxp/collector/base_collector.py
@@ -21,7 +21,9 @@ class BaseCollector:
         For use by custom collector
     '''
     @staticmethod
-    def info_collector(name, decription, router_records, metric_labels=[]):
+    def info_collector(name, decription, router_records, metric_labels=None):
+        if metric_labels is None:
+            metric_labels = []
         BaseCollector._add_id_labels(metric_labels)
         collector = InfoMetricFamily(f'mktxp_{name}', decription)
 
@@ -31,7 +33,9 @@ class BaseCollector:
         return collector
 
     @staticmethod
-    def counter_collector(name, decription, router_records, metric_key, metric_labels=[]):
+    def counter_collector(name, decription, router_records, metric_key, metric_labels=None):
+        if metric_labels is None:
+            metric_labels = []
         BaseCollector._add_id_labels(metric_labels)
         collector = CounterMetricFamily(f'mktxp_{name}', decription, labels=metric_labels)
 
@@ -41,7 +45,9 @@ class BaseCollector:
         return collector
 
     @staticmethod
-    def gauge_collector(name, decription, router_records, metric_key, metric_labels=[], add_id_labels = True):
+    def gauge_collector(name, decription, router_records, metric_key, metric_labels=None, add_id_labels = True):
+        if metric_labels is None:
+            metric_labels = []        
         if add_id_labels:
             BaseCollector._add_id_labels(metric_labels)
         collector = GaugeMetricFamily(f'mktxp_{name}', decription, labels=metric_labels)