diff --git a/src/TransientFETools/TransientFEOperators.jl b/src/TransientFETools/TransientFEOperators.jl
index 8a1a629..02b4f7f 100644
--- a/src/TransientFETools/TransientFEOperators.jl
+++ b/src/TransientFETools/TransientFEOperators.jl
@@ -193,11 +193,18 @@ function TransientFEOperator(res::Function,jac::Function,jac_t::Function,
 end
 
 function TransientFEOperator(res::Function,trial,test;order::Integer=1)
-  jacs = ()
-  for i in 1:order+1
+  function jac_0(t,x,dx0,dv)
+    function res_0(y)
+      x0 = (y,x[2:end]...)
+      res(t,x0,dv)
+    end
+    jacobian(res_0,x[1])
+  end
+  jacs = (jac_0,)
+  for i in 2:order+1
     function jac_i(t,x,dxi,dv)
       function res_i(y)
-        x[i] = y
+        x = (x[1:i-1]...,y,x[i+1:end]...)
         res(t,x,dv)
       end
       jacobian(res_i,x[i])
diff --git a/test/TransientFEsTests/HeatEquationAutoDiffTests.jl b/test/TransientFEsTests/HeatEquationAutoDiffTests.jl
index 3ec19eb..e548305 100644
--- a/test/TransientFEsTests/HeatEquationAutoDiffTests.jl
+++ b/test/TransientFEsTests/HeatEquationAutoDiffTests.jl
@@ -50,11 +50,11 @@ dv = get_fe_basis(V0)
 du = get_trial_fe_basis(U₀)
 uh = FEFunction(U₀,rand(num_free_dofs(U₀)))
 
-cell_j = get_array(jac(0.5,uh,uh,du,dv))
-cell_j_t = get_array(jac_t(0.5,uh,uh,du,dv))
+cell_j = get_array(jac(0.5,(uh,uh),du,dv))
+cell_j_t = get_array(jac_t(0.5,(uh,uh),du,dv))
 
-cell_j_auto = get_array(jacobian(x->res(0.5,x,uh,dv),uh))
-cell_j_t_auto = get_array(jacobian(x->res(0.5,uh,x,dv),uh))
+cell_j_auto = get_array(jacobian(x->res(0.5,(x,uh),dv),uh))
+cell_j_t_auto = get_array(jacobian(x->res(0.5,(uh,x),dv),uh))
 
 test_array(cell_j_auto,cell_j,≈)
 test_array(cell_j_t_auto,cell_j_t,≈)