diff --git a/src/QSymbolicsBase/predefined.jl b/src/QSymbolicsBase/predefined.jl
index bc15880..96af471 100644
--- a/src/QSymbolicsBase/predefined.jl
+++ b/src/QSymbolicsBase/predefined.jl
@@ -179,7 +179,7 @@ const CPHASE = CPHASEGate()
 
 abstract type AbstractSingleBosonOp <: Symbolic{AbstractOperator} end
 abstract type AbstractSingleBosonGate <: AbstractSingleBosonOp end # TODO maybe an IsUnitaryTrait is a better choice
-isexpr(::AbstractSingleBosonOp) = false
+isexpr(::AbstractSingleBosonGate) = false
 basis(::AbstractSingleBosonGate) = inf_fock_basis
 
 @withmetadata struct NumberOp <: AbstractSingleBosonOp end
diff --git a/src/QSymbolicsBase/rules.jl b/src/QSymbolicsBase/rules.jl
index 66494ae..d5e140c 100644
--- a/src/QSymbolicsBase/rules.jl
+++ b/src/QSymbolicsBase/rules.jl
@@ -104,8 +104,6 @@ RULES_EXPAND = [
     @rule(+(~~ops) * ~o1 => +(map(op -> op * ~o1, ~~ops)...)),
     @rule(⊗(~~ops1::_vecisa(Symbolic{AbstractBra})) * ⊗(~~ops2::_vecisa(Symbolic{AbstractKet})) => *(map(*, ~~ops1, ~~ops2)...)),
     @rule(⊗(~~ops1::_vecisa(Symbolic{AbstractOperator})) * ⊗(~~ops2::_vecisa(Symbolic{AbstractOperator})) => ⊗(map(*, ~~ops1, ~~ops2)...)),
-    @rule(~o1::_isa(Symbolic{AbstractOperator}) * ⊗(~~ops) => ⊗(map(op -> ~o1 * op, ~~ops)...)),
-    @rule(⊗(~~ops) * ~o1::_isa(Symbolic{AbstractOperator}) => ⊗(map(op -> op * ~o1, ~~ops)...)),
 ]
 
 # 
diff --git a/test/test_trace.jl b/test/test_trace.jl
index bc03e21..ef4f59a 100644
--- a/test/test_trace.jl
+++ b/test/test_trace.jl
@@ -23,6 +23,7 @@ exp2 = A⊗(B⊗C + D⊗E)
     @test isequal(ptrace(𝒪, 1), SPartialTrace(𝒪, 1))
     @test isequal(ptrace(𝒪, 2), SPartialTrace(𝒪, 2))
     @test isequal(ptrace(A, 1), tr(A))
+    @test isequal(ptrace(A*(B+C), 1), tr(A*B)+tr(A*C))
     @test_throws ArgumentError ptrace(A, 2)
     @test isequal(QuantumSymbolics.basis(ptrace(𝒪, 1)), SpinBasis(1//2))
     @test isequal(QuantumSymbolics.basis(ptrace(𝒪, 2)), SpinBasis(1//2))