diff --git a/src/primitive/time_evolution.jl b/src/primitive/time_evolution.jl
index 6036aba..4de560e 100644
--- a/src/primitive/time_evolution.jl
+++ b/src/primitive/time_evolution.jl
@@ -64,7 +64,7 @@ cache_key(te::TimeEvolution) = (te.dt, cache_key(te.H))
 # parametric interface
 niparams(::Type{<:TimeEvolution}) = 1
 getiparams(x::TimeEvolution) = x.dt
-setiparams!(r::TimeEvolution, param::Real) = (r.dt = param; r)
+setiparams!(r::TimeEvolution, param::Number) = (r.dt = param; r)
 
 function Base.:(==)(lhs::TimeEvolution, rhs::TimeEvolution)
     return lhs.H == rhs.H && lhs.dt == rhs.dt