diff --git a/test/1_test_sim_model.jl b/test/1_test_sim_model.jl
index 51f5cecef..e2eabb750 100644
--- a/test/1_test_sim_model.jl
+++ b/test/1_test_sim_model.jl
@@ -265,6 +265,10 @@ end
     @test_throws ErrorException NonLinModel(
         (x,u,_,_)->linmodel1.A*x + linmodel1.Bu*u,
         (x,_)->linmodel1.C*x, Ts, 2, 4, 2, 1, solver=nothing)
+
+    @test_throws ArgumentError RungeKutta(2)
+    @test_throws ArgumentError RungeKutta(0)
+    @test_throws ArgumentError RungeKutta(4, supersample=0)
 end
 
 @testitem "NonLinModel sim methods" setup=[SetupMPCtests] begin
diff --git a/test/5_test_extensions.jl b/test/5_test_extensions.jl
index cf0cabfc7..1384c0bd5 100644
--- a/test/5_test_extensions.jl
+++ b/test/5_test_extensions.jl
@@ -177,3 +177,24 @@ end
     u_data1, u_data2 = sim_wr(model, mpc1, mpc2, N)
     @test u_data1 ≈ u_data2 atol=1e-2 rtol=1e-2
 end
+
+@testitem "LinearMPCext unsupported features" setup=[SetupMPCtests] begin
+    using .SetupMPCtests, ControlSystemsBase, LinearAlgebra, JuMP, DAQP
+    import LinearMPC
+    optim = Model(DAQP.Optimizer)
+    model = LinModel(tf([2], [10, 1]), 3.0)
+    mpc = LinMPC(model, Hp=3, M_Hp=diagm([1, 1, 3]); optim)
+    @test_nowarn LinearMPC.MPC(mpc)
+    mpc = LinMPC(model, Hp=3, M_Hp=diagm([1, 2, 3]); optim)
+    @test_throws ErrorException LinearMPC.MPC(mpc)
+    mpc = LinMPC(model, Hc=3, N_Hc=diagm([1, 2, 3]); optim)
+    @test_throws ErrorException LinearMPC.MPC(mpc)
+    mpc = LinMPC(model, Hp=3, L_Hp=diagm([1, 2, 3]); optim)
+    @test_throws ErrorException LinearMPC.MPC(mpc)
+    mpc = setconstraint!(LinMPC(model; optim), c_ymin=[1], c_ymax=[0.5])
+    @test_throws ErrorException LinearMPC.MPC(mpc)
+    mpc = setconstraint!(LinMPC(model; optim), c_ymin=[0.5], c_ymax=[0.5])
+    @test_logs (:warn, 
+        "LinearMPC only supports softness parameters c = 0 or 1.\n"*
+        "All constraints with c > 0 will be considered soft.") LinearMPC.MPC(mpc)
+end
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