diff --git a/src/FESpaces/FEOperators.jl b/src/FESpaces/FEOperators.jl
index a946581c4..b9a44ea81 100644
--- a/src/FESpaces/FEOperators.jl
+++ b/src/FESpaces/FEOperators.jl
@@ -268,7 +268,7 @@ struct NonLinearFEOperator <:FEOperator
   testfesp::FESpaceLike
   trialfesp::FESpaceLike
   assem::AssemblerLike
-  terms::NTuple{N,<:FETerm} where N
+  terms::NTuple{N,FETerm} where N
 end
 
 function NonLinearFEOperator(
diff --git a/test/FESpacesTests/NonLinearFEOperatorsTests.jl b/test/FESpacesTests/NonLinearFEOperatorsTests.jl
index cb2714a1a..8800c8688 100644
--- a/test/FESpacesTests/NonLinearFEOperatorsTests.jl
+++ b/test/FESpacesTests/NonLinearFEOperatorsTests.jl
@@ -86,4 +86,13 @@ zh = zero(U)
 solve!(zh,solver,op,cache)
 @test free_dofs(zh) ≈ free_dofs(uh)
 
+t_Ω = NonLinearFETerm(res,jac,trian,quad)
+
+b0fun(x) = 0.0
+b0(v) = inner(v,b0fun)
+t_source = FESource(b0,trian,quad)
+
+op = NonLinearFEOperator(V,U,assem,t_Ω,t_source)
+op = NonLinearFEOperator(V,U,t_Ω,t_source)
+
 end # module NonLinearFEOperatorsTests