diff --git a/b_asic/signal_flow_graph.py b/b_asic/signal_flow_graph.py
index dd2c02c247f51a7da1c4e4d1b0a05328126d6a0c..bcfc9eebd7599128a92c83beafa64209fce6e43a 100644
--- a/b_asic/signal_flow_graph.py
+++ b/b_asic/signal_flow_graph.py
@@ -48,7 +48,6 @@ class SFG(AbstractOperation):
     _original_components_to_new: MutableSet[GraphComponent]
     _original_input_signals_to_indices: Dict[Signal, int]
     _original_output_signals_to_indices: Dict[Signal, int]
-    _dependency_map: Dict[int, MutableSet[int]]
 
     def __init__(self, input_signals: Optional[Sequence[Signal]] = None, output_signals: Optional[Sequence[Signal]] = None, \
                  inputs: Optional[Sequence[Input]] = None, outputs: Optional[Sequence[Output]] = None, \
@@ -72,7 +71,6 @@ class SFG(AbstractOperation):
         self._original_components_to_new = {}
         self._original_input_signals_to_indices = {}
         self._original_output_signals_to_indices = {}
-        self._dependency_map = {}
 
         # Setup input signals.
         if input_signals is not None: