diff --git a/src/greedy.py b/src/greedy.py
index 2c74a82..e686426 100644
--- a/src/greedy.py
+++ b/src/greedy.py
@@ -39,7 +39,8 @@ def explore_solutions(solutions, data, index):
 
 def remove_duplicates(current, previous, data):
     duplicate_free_df = data.query(
-        f"(source != {current} or destination not in @previous) and (source not in @previous or destination != {current})"
+        "(source != @current or destination not in @previous) and \
+        (source not in @previous or destination != @current)"
     )
     return duplicate_free_df
 
diff --git a/src/local_search.py b/src/local_search.py
index 3567ba6..8237dee 100644
--- a/src/local_search.py
+++ b/src/local_search.py
@@ -9,7 +9,8 @@ def get_first_random_solution(m, data):
 
 def element_in_dataframe(solution, element):
     duplicates = solution.query(
-        f"(source == {element.source} and destination == {element.destination}) or (source == {element.destination} and destination == {element.source})"
+        f"(source == {element.source} and destination == {element.destination}) or \
+        (source == {element.destination} and destination == {element.source})"
     )
     return not duplicates.empty