diff --git a/src/perform_step/sdirk_perform_step.jl b/src/perform_step/sdirk_perform_step.jl
index efcee3e2e9..7fd7507853 100644
--- a/src/perform_step/sdirk_perform_step.jl
+++ b/src/perform_step/sdirk_perform_step.jl
@@ -97,7 +97,7 @@ end
     z .= zero(eltype(u))
   end
 
-  nlsolver.tmp = uprev
+  nlsolver.tmp .= uprev
   z = nlsolve!(integrator, cache)
   nlsolvefail(nlsolver) && return
   @.. u = uprev + z