diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 392a42ce..850ebeec 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -33,7 +33,7 @@ jobs:
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v4
+      - uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: lcov.info
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f2f7e872..ab7f49d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.5.9
+ - fix regression for `Union{Bool,Nothing}` array elements (#617)
+ - fix printing issue in `printtoc` 
+
 ## 0.5.8
  - Stop using `Base.module_keys` as it is removed on nightly
 
diff --git a/Project.toml b/Project.toml
index 71b75d7b..a86f6234 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "JLD2"
 uuid = "033835bb-8acc-5ee8-8aae-3f567f8a3819"
-version = "0.5.8"
+version = "0.5.9"
 
 [deps]
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"
diff --git a/src/JLD2.jl b/src/JLD2.jl
index cc868753..3d6d45c9 100644
--- a/src/JLD2.jl
+++ b/src/JLD2.jl
@@ -462,8 +462,10 @@ Prints an overview of the contents of `f` to the `IO`.
 Use the optional `numlines` parameter to restrict the amount of items listed.
 """
 printtoc(f::JLDFile; kwargs...) = printtoc(Base.stdout, f; kwargs...)
-printtoc(io::IO, f::JLDFile; numlines = typemax(Int64)) =
+function printtoc(io::IO, f::JLDFile; numlines = typemax(Int64))
     show_group(io, f.root_group, numlines, " ", true)
+    return nothing
+end
 
 
 
diff --git a/src/inlineunion.jl b/src/inlineunion.jl
index cba8aa84..cce81247 100644
--- a/src/inlineunion.jl
+++ b/src/inlineunion.jl
@@ -52,9 +52,9 @@ end
 # except for the ReadRepresentation and the very last line where the data is
 # converted back into a Union Array
 function read_array(f::JLDFile, dataspace::ReadDataspace,
-                    rr::MappedRepr{InlineUnionEl{T1,T2},RR}, layout::DataLayout,
+                    rr::ReadRepresentation{InlineUnionEl{T1,T2},RR}, layout::DataLayout,
                     filters::FilterPipeline, header_offset::RelOffset,
-                    attributes::Union{Vector{ReadAttribute},Nothing}) where {T1, T2,RR}
+                    attributes::Union{Vector{ReadAttribute},Nothing}) where {T1,T2,RR}
     io = f.io
     ndims, offset = get_ndims_offset(f, dataspace, attributes)
     seek(io, offset)
diff --git a/test/inlineunion.jl b/test/inlineunion.jl
index 5657b918..6a360762 100644
--- a/test/inlineunion.jl
+++ b/test/inlineunion.jl
@@ -40,4 +40,8 @@ struct Bparam{T}; x::T; end
     u = Union{Float32, Missing}[rand(5,5);]
     save(fn, "u", u)
     @test u == load(fn, "u")
+
+    u = Union{Bool, Nothing}[true, nothing, false]
+    save(fn, "u", u)
+    @test u == load(fn, "u")
 end