diff --git a/src/algorithms/derivatives/mpo_derivatives.jl b/src/algorithms/derivatives/mpo_derivatives.jl
index 67e47dbee..1fb1654f6 100644
--- a/src/algorithms/derivatives/mpo_derivatives.jl
+++ b/src/algorithms/derivatives/mpo_derivatives.jl
@@ -323,7 +323,7 @@ function (H::PrecomputedCDerivative)(x::MPSBondTensor)
 
     TC = TensorOperations.promote_contract(scalartype(x), scalartype(H))
     xR = TensorOperations.tensoralloc_contract(
-        TC, x, ((1,), (2,)), false, R, ((1,), (2, 3)), false, ((1, 2), (3,)), Val(true), allocator
+        TC, x, ((1,), (2,)), false, R, ((1,), (3, 2)), false, ((1, 3), (2,)), Val(true), allocator
     )
     mul_front!(xR, x, R, One(), Zero(), backend, allocator)
     LxR = L * xR
diff --git a/test/symmetries/multifusion.jl b/test/symmetries/multifusion.jl
index 3096062a2..d050381d7 100644
--- a/test/symmetries/multifusion.jl
+++ b/test/symmetries/multifusion.jl
@@ -53,14 +53,14 @@ module TestMultifusion
 
     @testset "InfiniteMPS construction" begin
         for (P, V) in bad_fusions
-            @test_throws ArgumentError InfiniteMPS([P], [V])
+            @test_throws SpaceMismatch InfiniteMPS([P], [V])
         end
     end
 
     @testset "FiniteMPS construction" begin
         for (P, V) in bad_fusions
-            @test_warn "no fusion channels available at site 2" FiniteMPS(rand(2:100), P, V)
-            @test_warn "no fusion channels available at site 2" FiniteMPS(rand(2:100), P, V; left = V, right = V)
+            @test_throws ArgumentError FiniteMPS(rand(2:100), P, V)
+            @test_throws SpaceMismatch FiniteMPS(rand(2:100), P, V; left = V, right = V)
         end
     end