diff --git a/orangecontrib/storynavigation/modules/actionanalysis.py b/orangecontrib/storynavigation/modules/actionanalysis.py
index 4df7daf..9807ef4 100644
--- a/orangecontrib/storynavigation/modules/actionanalysis.py
+++ b/orangecontrib/storynavigation/modules/actionanalysis.py
@@ -221,8 +221,8 @@ def __filter_custom_word_matches(self, story_elements_df, selected_stories, cust
             current_frame['classification'] = c_col
             current_frame.rename(columns={cust_tag_col: 'category'}, inplace=True)
             combined_df = pd.concat([combined_df, current_frame], axis=0)
-
-        combined_df = combined_df[combined_df['category'] not in ['?', 'nan']]
+        
+        combined_df = combined_df[~combined_df['category'].isin(['?', 'nan'])]
         return combined_df.reset_index(drop=True)
     
     def calculate_customfreq_table(self, df, selected_stories=None):
diff --git a/orangecontrib/storynavigation/modules/actoranalysis.py b/orangecontrib/storynavigation/modules/actoranalysis.py
index c5e51a3..e58e0c0 100644
--- a/orangecontrib/storynavigation/modules/actoranalysis.py
+++ b/orangecontrib/storynavigation/modules/actoranalysis.py
@@ -46,8 +46,9 @@ def __filter_custom_word_matches(self, story_elements_df, selected_stories, cust
             current_frame['classification'] = c_col
             current_frame.rename(columns={cust_tag_col: 'category'}, inplace=True)
             combined_df = pd.concat([combined_df, current_frame], axis=0)
-        
-        combined_df = combined_df[combined_df['category'] not in ['?', 'nan']]
+                
+        combined_df = combined_df[~combined_df['category'].isin(['?', 'nan'])]
+
         return combined_df.reset_index(drop=True)
 
     def __filter_rows(self, story_elements_df, pos_tags):