diff --git a/lib/ModelingToolkitTearing/src/clock_inference/clock_inference.jl b/lib/ModelingToolkitTearing/src/clock_inference/clock_inference.jl
index 5a802b9..2398e58 100644
--- a/lib/ModelingToolkitTearing/src/clock_inference/clock_inference.jl
+++ b/lib/ModelingToolkitTearing/src/clock_inference/clock_inference.jl
@@ -152,18 +152,21 @@ function (iec::InferEquationClosure)(ieq::Int, eq::Equation, is_initialization_e
         end
 
         outdomain = output_timedomain(op)
-        @match outdomain begin
-            x::SciMLBase.AbstractClock => begin
-                push!(hyperedge, ClockVertex.Clock(x))
-            end
-            InferredClock.Inferred() => nothing
-            InferredClock.InferredDiscrete(i) => begin
-                buffer = get(relative_hyperedges, i, nothing)
-                if buffer !== nothing
-                    union!(hyperedge, buffer)
-                    delete!(relative_hyperedges, i)
+        if outdomain isa SciMLBase.AbstractClock
+            push!(hyperedge, ClockVertex.Clock(outdomain))
+        elseif outdomain isa InferredTimeDomain
+            @match outdomain begin
+                InferredClock.Inferred() => nothing
+                InferredClock.InferredDiscrete(i) => begin
+                    buffer = get(relative_hyperedges, i, nothing)
+                    if buffer !== nothing
+                        union!(hyperedge, buffer)
+                        delete!(relative_hyperedges, i)
+                    end
                 end
             end
+        else
+            error("Unreachable reached!")
         end
 
         for (_, relative_edge) in relative_hyperedges
diff --git a/lib/ModelingToolkitTearing/src/clock_inference/interface.jl b/lib/ModelingToolkitTearing/src/clock_inference/interface.jl
index bd92c9f..2024ff1 100644
--- a/lib/ModelingToolkitTearing/src/clock_inference/interface.jl
+++ b/lib/ModelingToolkitTearing/src/clock_inference/interface.jl
@@ -75,7 +75,7 @@ function system_subset(ts::TearingState, ieqs::Vector{Int}, iieqs::Vector{Int},
     @set! ts.structure = system_subset(ts.structure, ieqs, ivars)
     if all(eq -> eq.rhs isa StateMachineOperator, MTKBase.get_eqs(ts.sys))
         names = Symbol[]
-        for eq in get_eqs(ts.sys)
+        for eq in MTKBase.get_eqs(ts.sys)
             if eq.lhs isa Transition
                 push!(names, first(MTKBase.namespace_hierarchy(nameof(eq.rhs.from))))
                 push!(names, first(MTKBase.namespace_hierarchy(nameof(eq.rhs.to))))
diff --git a/lib/ModelingToolkitTearing/src/clock_inference/state_machines.jl b/lib/ModelingToolkitTearing/src/clock_inference/state_machines.jl
index ca01ea9..cd87ad1 100644
--- a/lib/ModelingToolkitTearing/src/clock_inference/state_machines.jl
+++ b/lib/ModelingToolkitTearing/src/clock_inference/state_machines.jl
@@ -76,14 +76,6 @@ for (s, T) in [(:timeInState, :Real),
     @eval begin
         $s(x) = wrap(term($s, x))
         SymbolicUtils.promote_symtype(::typeof($s), ::Type{S}) where {S} = $T
-        function SymbolicUtils.show_call(io, ::typeof($s), args)
-            if isempty(args)
-                print(io, $s, "()")
-            else
-                arg = only(args)
-                print(io, $s, "(", arg isa Number ? arg : nameof(arg), ")")
-            end
-        end
     end
     if s != :activeState
         @eval $s() = wrap(term($s))
diff --git a/lib/ModelingToolkitTearing/src/reassemble.jl b/lib/ModelingToolkitTearing/src/reassemble.jl
index b316ce6..375c41f 100644
--- a/lib/ModelingToolkitTearing/src/reassemble.jl
+++ b/lib/ModelingToolkitTearing/src/reassemble.jl
@@ -782,7 +782,7 @@ function codegen_equation!(eg::EquationGenerator,
             # current time. This works because we added one additional history element
             # in `add_additional_history!`.
             if isdisc
-                neweq = backshift_expr(neweq, idep)
+                neweq = backshift_expr(neweq, idep::SymbolicT)::Equation
             end
             push!(solved_eqs, neweq)
             push!(solved_vars, iv)
@@ -794,7 +794,7 @@ function codegen_equation!(eg::EquationGenerator,
         neweq = make_algebraic_equation(eq, total_sub)
         # For the same reason as solved equations (they are effectively the same)
         if isdisc
-            neweq = backshift_expr(neweq, idep)
+            neweq = backshift_expr(neweq, idep::SymbolicT)
         end
         push!(neweqs′, neweq)
         push!(eq_ordering, ieq)
@@ -982,7 +982,7 @@ function update_simplified_system!(
     end
     @set! sys.unknowns = unknowns
 
-    obs = tearing_hacks(sys, obs, unknowns, neweqs; array = array_hack)
+    obs = (@invokelatest tearing_hacks(sys, obs, unknowns, neweqs; array = array_hack))::Vector{Equation}
 
     @set! sys.eqs = neweqs
     @set! sys.observed = obs
@@ -1240,7 +1240,7 @@ Backshift the given expression `ex`.
 function backshift_expr(ex, iv)
     ex isa SymbolicT || return ex
     return descend_lower_shift_varname_with_unit(
-        MTKBase.simplify_shifts(MTKBase.distribute_shift(Shift(iv, -1)(ex))), iv)
+        MTKBase.simplify_shifts(MTKBase.distribute_shift(Shift(iv, -1)(ex))), iv)::SymbolicT
 end
 
 function backshift_expr(ex::Equation, iv)
@@ -1298,26 +1298,30 @@ function tearing_hacks(sys, obs, unknowns, neweqs; array = true)
         rhs = eq.rhs
 
         array || continue
-        iscall(lhs) || continue
-        operation(lhs) === getindex || continue
-        SU.shape(lhs) isa SU.Unknown && continue
-        arg1 = arguments(lhs)[1]
-        cnt = get(arr_obs_occurrences, arg1, 0)
-        arr_obs_occurrences[arg1] = cnt + 1
-        continue
+        Moshi.Match.@match lhs begin
+            BSImpl.Term(; f, args) && if f === getindex end => begin
+                arg1 = args[1]
+                cnt = get(arr_obs_occurrences, arg1, 0)
+                arr_obs_occurrences[arg1] = cnt + 1
+            end
+            _ => nothing
+        end
     end
 
     # count variables in unknowns if they are scalarized forms of variables
     # also present as observed. e.g. if `x[1]` is an unknown and `x[2] ~ (..)`
     # is an observed equation.
     for sym in unknowns
-        iscall(sym) || continue
-        operation(sym) === getindex || continue
-        SU.shape(sym) isa SU.Unknown && continue
-        arg1 = arguments(sym)[1]
-        cnt = get(arr_obs_occurrences, arg1, 0)
-        cnt == 0 && continue
-        arr_obs_occurrences[arg1] = cnt + 1
+        Moshi.Match.@match sym begin
+            BSImpl.Term(; f, args, shape) && if f === getindex end => begin
+                shape isa SU.Unknown && continue
+                arg1 = args[1]
+                cnt = get(arr_obs_occurrences, arg1, 0)
+                cnt == 0 && continue
+                arr_obs_occurrences[arg1] = cnt + 1
+            end
+            _ => nothing
+        end
     end
 
     obs_arr_eqs = Equation[]
diff --git a/lib/ModelingToolkitTearing/src/tearingstate.jl b/lib/ModelingToolkitTearing/src/tearingstate.jl
index f677a71..066c622 100644
--- a/lib/ModelingToolkitTearing/src/tearingstate.jl
+++ b/lib/ModelingToolkitTearing/src/tearingstate.jl
@@ -207,7 +207,7 @@ function TearingState(sys::System; check::Bool = true, sort_eqs::Bool = true)
                     addvar!(vi, VARIABLE)
                 end
             else
-                vv = collect(v)::Array{SymbolicT}
+                vv = vec(collect(v)::Array{SymbolicT})::Vector{SymbolicT}
                 union!(incidence, vv)
                 for vi in vv
                     addvar!(vi, VARIABLE)
@@ -456,7 +456,7 @@ end
 function lower_order_var(dervar::SymbolicT, t::SymbolicT)
     @match dervar begin
         BSImpl.Term(; f, args) && if f isa Differential end => begin
-            order = f.order::Int
+            order::Int = f.order::Int
             isone(order) && return args[1]
             return Differential(f.x, order - 1)(args[1])
         end
diff --git a/lib/ModelingToolkitTearing/src/utils.jl b/lib/ModelingToolkitTearing/src/utils.jl
index 8c86347..c5f12a0 100644
--- a/lib/ModelingToolkitTearing/src/utils.jl
+++ b/lib/ModelingToolkitTearing/src/utils.jl
@@ -20,14 +20,18 @@ function descend_lower_shift_varname_with_unit(var, iv)
     MTKBase._with_unit(descend_lower_shift_varname, var, iv, iv)
 end
 function descend_lower_shift_varname(var, iv)
-    iscall(var) || return var
-    op = operation(var)
-    if op isa Shift
-        return MTKBase.shift2term(var)
-    else
-        args = arguments(var)
-        args = map(Base.Fix2(descend_lower_shift_varname, iv), args)
-        return SU.maketerm(SymbolicT, op, args, SU.metadata(var))
+    @match var begin
+        BSImpl.Term(; f, args) && if f isa Shift end => MTKBase.shift2term(var)
+        if iscall(var) end => begin
+            args = arguments(var)
+            _args = SU.ArgsT{VartypeT}()
+            sizehint!(_args, length(args))
+            for arg in args
+                push!(_args, descend_lower_shift_varname(arg, iv))
+            end
+            return SU.maketerm(SymbolicT, operation(var), _args, SU.metadata(var))
+        end
+        _ => return var
     end
 end