diff --git a/src/ReachSets/ReachSets.jl b/src/ReachSets/ReachSets.jl
index 6bb74f49..b5b5e92c 100644
--- a/src/ReachSets/ReachSets.jl
+++ b/src/ReachSets/ReachSets.jl
@@ -86,7 +86,7 @@ include("DiscretePost/DiscretePost.jl")
 export PostOperator,
        ContinuousPost,
        DiscretePost,
-       init,
+       init, init!,
        post,
        tube⋂inv!
 
diff --git a/src/solve.jl b/src/solve.jl
index a6c7fc5f..feaba999 100644
--- a/src/solve.jl
+++ b/src/solve.jl
@@ -63,7 +63,7 @@ function solve!(system::InitialValueProblem{<:Union{AbstractContinuousSystem,
                 invariant::Union{LazySet, Nothing}=nothing
                )::AbstractSolution
     system = normalize(system)
-    options = init(op, system, options_input)
+    options = init!(op, system, options_input)
 
     # coordinate transformation
     if options[:coordinate_transformation] != ""
@@ -115,7 +115,7 @@ function solve!(system::InitialValueProblem{<:HybridSystem,
 
     HS = system.s
     init_sets = system.x0
-    options = init(opD, HS, options_input)
+    options = init!(opD, HS, options_input)
     time_horizon = options[:T]
     max_jumps = options[:max_jumps]
     inout_map = nothing