diff --git a/src/builders/interface.jl b/src/builders/interface.jl
index bb8c9e6c8..bde95e6c4 100644
--- a/src/builders/interface.jl
+++ b/src/builders/interface.jl
@@ -55,10 +55,6 @@ function interface_constraints(
         prep(id, (mod, mod[interface]))
     prep(id::Symbol, (mod, interface, multiplier)::Tuple{C.ConstraintTree,Symbol,<:Real}) =
         prep(id, (mod, C.map(c -> c * multiplier, mod[interface])))
-    prep(
-        id::Symbol,
-        (mod, interface, multiplier)::Tuple{C.ConstraintTree,C.ConstraintTree,<:Real},
-    ) = prep(id, (mod, C.map(c -> c * multiplier, interface)))
     prep(id::Symbol, (mod, interface)::Tuple{C.ConstraintTreeElem,C.ConstraintTreeElem}) =
         (id^(:network^mod * :interface^interface))
     prep_pair((a, b)) = prep(a, b)