diff --git a/src/LinearSolvers/Krylov/KrylovUtils.jl b/src/LinearSolvers/Krylov/KrylovUtils.jl
index 55335d77..dcd76b11 100644
--- a/src/LinearSolvers/Krylov/KrylovUtils.jl
+++ b/src/LinearSolvers/Krylov/KrylovUtils.jl
@@ -19,6 +19,9 @@ function krylov_mul!(y,A,x,Pr::Nothing,Pl,wr,wl)
   mul!(wl,A,x)
   solve!(y,Pl,wl)
 end
+function krylov_mul!(y,A,x,Pr::Nothing,Pl::Nothing,wr,wl)
+  mul!(y,A,x)
+end
 
 """
   Computes the Krylov residual r = Pl⁻¹(A⋅x - b).
diff --git a/test/LinearSolvers/KrylovSolversTests.jl b/test/LinearSolvers/KrylovSolversTests.jl
index 9bf8fe51..94a35495 100644
--- a/test/LinearSolvers/KrylovSolversTests.jl
+++ b/test/LinearSolvers/KrylovSolversTests.jl
@@ -64,9 +64,14 @@ function main(distribute,np)
   P = JacobiLinearSolver()
   verbose = i_am_main(parts)
 
+  # GMRES with left and right preconditioner
   gmres = LinearSolvers.GMRESSolver(40;Pr=P,Pl=P,rtol=1.e-8,verbose=verbose)
   test_solver(gmres,op,Uh,dΩ)
 
+  # GMRES without preconditioner
+  gmres = LinearSolvers.GMRESSolver(40;rtol=1.e-8,verbose=verbose)
+  test_solver(gmres,op,Uh,dΩ)
+
   fgmres = LinearSolvers.FGMRESSolver(40,P;rtol=1.e-8,verbose=verbose)
   test_solver(fgmres,op,Uh,dΩ)