diff --git a/lib/dl_api_lib/dl_api_lib_tests/db/data_api/result/complex_queries/test_lookup_functions.py b/lib/dl_api_lib/dl_api_lib_tests/db/data_api/result/complex_queries/test_lookup_functions.py
index 906e0e702..2b842848c 100644
--- a/lib/dl_api_lib/dl_api_lib_tests/db/data_api/result/complex_queries/test_lookup_functions.py
+++ b/lib/dl_api_lib/dl_api_lib_tests/db/data_api/result/complex_queries/test_lookup_functions.py
@@ -86,9 +86,11 @@ def test_ago_filtered(self, control_api, data_api, saved_dataset):
         assert result_resp.status_code == HTTPStatus.OK, result_resp.json
 
         query: str = result_resp.json["blocks"][0]["query"]
-        expected_query_pattern = r"JOIN[\S\s]*\([\S\s]*order_date[\S\s]*5[\S\s]*>=[\S\s]*2014-01-06[\S\s]*\)[\S\s]*ON"
+        expected_query_pattern = r"JOIN.*\(.*order_date.*5.*>=.*2014-01-06.*\).*ON"
         assert re.search(
-            expected_query_pattern, query
+            expected_query_pattern,
+            query,
+            flags=re.DOTALL,
         ), "Expected to find pattern 'JOIN (... order_date >= 2014-01-06 ...) ON' in query"
 
     def test_ago_variants(self, control_api, data_api, saved_dataset):
diff --git a/lib/dl_formula/dl_formula/inspect/expression.py b/lib/dl_formula/dl_formula/inspect/expression.py
index c07ab6537..9433890f4 100644
--- a/lib/dl_formula/dl_formula/inspect/expression.py
+++ b/lib/dl_formula/dl_formula/inspect/expression.py
@@ -452,17 +452,6 @@ def contains_lookup_functions(node: nodes.FormulaItem) -> bool:
     return False
 
 
-def contains_node(node: nodes.FormulaItem, target_node: nodes.FormulaItem) -> bool:
-    if node == target_node:
-        return True
-
-    for child in autonomous_children(node):
-        if contains_node(child, target_node):
-            return True
-
-    return False
-
-
 def resolve_dimensions(
     node_stack: Iterable[nodes.FormulaItem],
     dimensions: List[nodes.FormulaItem],  # TODO: rename to global_dimensions
diff --git a/lib/dl_query_processing/dl_query_processing/multi_query/splitters/query_fork.py b/lib/dl_query_processing/dl_query_processing/multi_query/splitters/query_fork.py
index 06c013bbb..04cd22050 100644
--- a/lib/dl_query_processing/dl_query_processing/multi_query/splitters/query_fork.py
+++ b/lib/dl_query_processing/dl_query_processing/multi_query/splitters/query_fork.py
@@ -11,7 +11,6 @@
 import dl_formula.core.nodes as formula_nodes
 from dl_formula.inspect.env import InspectionEnvironment
 import dl_formula.inspect.expression as inspect_expression
-from dl_formula.inspect.expression import contains_node
 import dl_formula.inspect.node as inspect_node
 from dl_formula.mutation.mutation import (
     FormulaMutation,
@@ -462,13 +461,10 @@ def get_split_masks(
             for filter_idx, filter_formula in enumerate(query.filters):
                 if filter_formula.original_field_id in qfork_info.bfb_field_ids:
                     # Filter field is in BFB, so exclude it unless it is mutated by one of the BFB mutations
-                    if any(
-                        contains_node(filter_formula.formula_obj, mutation.original)
-                        for mutation in qfork_info.bfb_filter_mutations
-                    ):
-                        new_filter = filter_formula.clone(
-                            formula_obj=apply_mutations(filter_formula.formula_obj, qfork_info.bfb_filter_mutations),
-                        )
+                    new_formula_obj = apply_mutations(filter_formula.formula_obj, qfork_info.bfb_filter_mutations)
+
+                    if new_formula_obj is not filter_formula.formula_obj:
+                        new_filter = filter_formula.clone(formula_obj=new_formula_obj)
                         add_filters.append(new_filter)
                     continue
                 if filter_idx in split_filter_indices: