diff --git a/b_asic/signal_flow_graph.py b/b_asic/signal_flow_graph.py
index 45a4d11686bbec81e83ecbd9b51758079d1f03cf..befbd67014d22f2790fbdc726250b6d7a11c0bf8 100644
--- a/b_asic/signal_flow_graph.py
+++ b/b_asic/signal_flow_graph.py
@@ -759,7 +759,7 @@ class SFG(AbstractOperation):
             The source operation GraphID to connect to.
         new_operation : Operation
             The new operation, e.g. Multiplication.
-        port: Optional[int]
+        port : Optional[int]
             The number of the InputPort before which the new operation shall be inserted
         """