diff --git a/pm4py/discovery.py b/pm4py/discovery.py
index df7164670..1515164ed 100644
--- a/pm4py/discovery.py
+++ b/pm4py/discovery.py
@@ -24,6 +24,7 @@
 """
 
 from typing import Tuple, Union, List, Dict, Any, Optional, Set
+from collections import Counter
 
 import pandas as pd
 from pandas import DataFrame
diff --git a/pm4py/filtering.py b/pm4py/filtering.py
index 93426c6c3..29f5e5597 100644
--- a/pm4py/filtering.py
+++ b/pm4py/filtering.py
@@ -24,6 +24,7 @@
 """
 
 from typing import Union, Set, List, Tuple, Collection, Any, Dict, Optional
+from collections import Counter
 
 import pandas as pd