diff --git a/src/serialization.jl b/src/serialization.jl
index f18ec14b1..f9999a905 100644
--- a/src/serialization.jl
+++ b/src/serialization.jl
@@ -265,6 +265,16 @@ serialize(uuids::Vector{Base.UUID}) = serialize.(uuids)
 serialize(uuids::Set{Base.UUID}) = serialize.(uuids)
 deserialize(::Type{Base.UUID}, data::Dict) = Base.UUID(data["value"])
 
+# IS serializes a Base.UUID as Dict("value" => string). The default
+# deserialize(::Type{T}, ::Any) = deepcopy(data) leaves the dicts unconverted,
+# so structs with Vector{Base.UUID} or Set{Base.UUID} fields
+# (e.g. Outage.monitored_components) would receive Vector{Dict} at construction
+# time. Convert each element here.
+deserialize(::Type{Vector{Base.UUID}}, data::AbstractVector) =
+    Base.UUID[deserialize(Base.UUID, x) for x in data]
+deserialize(::Type{Set{Base.UUID}}, data::AbstractVector) =
+    Set{Base.UUID}(deserialize(Base.UUID, x) for x in data)
+
 serialize(value::Complex) = Dict("real" => real(value), "imag" => imag(value))
 deserialize(::Type{Complex}, data::Dict) = Complex(data["real"], data["imag"])
 deserialize(::Type{Complex{T}}, data::Dict) where {T} =
diff --git a/test/test_serialization.jl b/test/test_serialization.jl
index b6fcc8810..fcdfbe18f 100644
--- a/test/test_serialization.jl
+++ b/test/test_serialization.jl
@@ -72,6 +72,32 @@ end
     @test IS.serialize(nt_result) == nt_data
 end
 
+@testset "Test Vector{Base.UUID} Serialization/Deserialization" begin
+    uuids = [Base.UUID(rand(UInt128)) for _ in 1:3]
+    serialized = IS.serialize(uuids)
+    @test serialized isa Vector{<:Dict}
+    @test all(d -> haskey(d, "value"), serialized)
+    deserialized = IS.deserialize(Vector{Base.UUID}, serialized)
+    @test deserialized isa Vector{Base.UUID}
+    @test deserialized == uuids
+    # Round-trip through JSON to mimic on-disk format.
+    json_round_trip = JSON3.read(JSON3.write(serialized), Vector{Dict})
+    @test IS.deserialize(Vector{Base.UUID}, json_round_trip) == uuids
+end
+
+@testset "Test Set{Base.UUID} Serialization/Deserialization" begin
+    uuids = Set(Base.UUID(rand(UInt128)) for _ in 1:3)
+    serialized = IS.serialize(uuids)
+    @test serialized isa Vector{<:Dict}
+    @test all(d -> haskey(d, "value"), serialized)
+    deserialized = IS.deserialize(Set{Base.UUID}, serialized)
+    @test deserialized isa Set{Base.UUID}
+    @test deserialized == uuids
+    # Round-trip through JSON to mimic on-disk format.
+    json_round_trip = JSON3.read(JSON3.write(serialized), Vector{Dict})
+    @test IS.deserialize(Set{Base.UUID}, json_round_trip) == uuids
+end
+
 @testset "Test JSON serialization of system data" begin
     for in_memory in (true, false)
         sys = create_system_data_shared_time_series(; time_series_in_memory = in_memory)