diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 1608d046..db0058b6 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -8,7 +8,7 @@ on:
 
 jobs:
   test:
-    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }}
+    name: ${{ matrix.downgrade && 'Downgrade / ' || '' }}Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -21,13 +21,21 @@ jobs:
           - ubuntu-latest
         arch:
           - x64
+        downgrade:
+          - false
         include:
           - version: '1'
             os: macOS-latest
             arch: x64
+            downgrade: false
           - version: '1'
             os: windows-latest
             arch: x64
+            downgrade: false
+          - version: '1'
+            os: ubuntu-latest
+            arch: x64
+            downgrade: true
     steps:
       - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v1
@@ -35,6 +43,11 @@ jobs:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
       - uses: julia-actions/cache@v1
+      - uses: cjdoris/julia-downgrade-compat-action@v1
+        with:
+          skip: LinearAlgebra,Markdown,Printf,Random,Statistics,Test
+        if: ${{ matrix.downgrade }}
+        name: Downgrade dependencies to oldest supported versions
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
         with:
diff --git a/Project.toml b/Project.toml
index 1535110f..31dd2a08 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "MCMCDiagnosticTools"
 uuid = "be115224-59cd-429b-ad48-344e309966f0"
 authors = ["David Widmann", "Seth Axen"]
-version = "0.3.8"
+version = "0.3.9"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
@@ -18,16 +18,49 @@ StatsFuns = "4c63d2b9-4356-54db-8cca-17b64c39e42c"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
 
 [compat]
+Aqua = "0.8.1"
 AbstractFFTs = "0.5, 1"
-DataAPI = "1.6"
+DataAPI = "1.8"
 DataStructures = "0.18.3"
-Distributions = "0.25"
+Distributions = "0.25.57"
+DynamicHMC = "3.2"
+EvoTrees = "0.15, 0.16"
+FFTW = "1.1"
 LinearAlgebra = "1.6"
+LogDensityProblems = "0.12, 1, 2"
+LogExpFunctions = "0.3.26"
+MLJBase = "0.20, 0.21, 1"
+MLJDecisionTreeInterface = "0.3, 0.4"
+MLJIteration = "0.5, 0.6"
+MLJLIBSVMInterface = "0.2"
 MLJModelInterface = "1.6"
+MLJModels = "0.16"
+MLJXGBoostInterface = "0.3.4"
+OffsetArrays = "1.11"
 Random = "1.6"
-SpecialFunctions = "0.8, 0.9, 0.10, 1, 2"
+SpecialFunctions = "1.8.4, 2"
 Statistics = "1.6"
-StatsBase = "0.33, 0.34"
+StatsBase = "0.33.3, 0.34"
 StatsFuns = "1"
-Tables = "1"
+Tables = "1.11"
+Test = "1.6"
 julia = "1.6"
+
+[extras]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+DynamicHMC = "bbc10e6e-7c05-544b-b16e-64fede858acb"
+EvoTrees = "f6006082-12f8-11e9-0c9c-0d5d367ab1e5"
+FFTW = "7a1cc6ca-52ef-59f5-83cd-3a7055c09341"
+LogDensityProblems = "6fdf6af0-433a-55f7-b3ed-c6c6e0b8df7c"
+LogExpFunctions = "2ab3a3ac-af41-5b50-aa03-7779005ae688"
+MLJBase = "a7f614a8-145f-11e9-1d2a-a57a1082229d"
+MLJDecisionTreeInterface = "c6f25543-311c-4c74-83dc-3ea6d1015661"
+MLJIteration = "614be32b-d00c-4edb-bd02-1eb411ab5e55"
+MLJLIBSVMInterface = "61c7150f-6c77-4bb1-949c-13197eac2a52"
+MLJModels = "d491faf4-2d78-11e9-2867-c94bc002c0b7"
+MLJXGBoostInterface = "54119dfa-1dab-4055-a167-80440f4f7a91"
+OffsetArrays = "6fe1bfb0-de20-5000-8ca7-80f57d26f881"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Aqua", "DynamicHMC", "EvoTrees", "FFTW", "LogDensityProblems", "LogExpFunctions", "MLJBase", "MLJDecisionTreeInterface", "MLJIteration", "MLJLIBSVMInterface", "MLJModels", "MLJXGBoostInterface", "OffsetArrays", "Test"]
diff --git a/docs/Project.toml b/docs/Project.toml
index 4bb663da..bf6ae5f0 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -9,8 +9,8 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
 Documenter = "1"
-EvoTrees = "0.14.7, 0.15, 0.16"
-MLJBase = "0.19, 0.20, 0.21, 1"
+EvoTrees = "0.15, 0.16"
+MLJBase = "0.20, 0.21, 1"
 MLJIteration = "0.5, 0.6"
 StatisticalMeasures = "0.1"
 Statistics = "1.6"
diff --git a/test/Project.toml b/test/Project.toml
deleted file mode 100644
index 630e595b..00000000
--- a/test/Project.toml
+++ /dev/null
@@ -1,40 +0,0 @@
-[deps]
-Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
-Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
-DynamicHMC = "bbc10e6e-7c05-544b-b16e-64fede858acb"
-EvoTrees = "f6006082-12f8-11e9-0c9c-0d5d367ab1e5"
-FFTW = "7a1cc6ca-52ef-59f5-83cd-3a7055c09341"
-LogDensityProblems = "6fdf6af0-433a-55f7-b3ed-c6c6e0b8df7c"
-LogExpFunctions = "2ab3a3ac-af41-5b50-aa03-7779005ae688"
-MLJBase = "a7f614a8-145f-11e9-1d2a-a57a1082229d"
-MLJDecisionTreeInterface = "c6f25543-311c-4c74-83dc-3ea6d1015661"
-MLJIteration = "614be32b-d00c-4edb-bd02-1eb411ab5e55"
-MLJLIBSVMInterface = "61c7150f-6c77-4bb1-949c-13197eac2a52"
-MLJModels = "d491faf4-2d78-11e9-2867-c94bc002c0b7"
-MLJXGBoostInterface = "54119dfa-1dab-4055-a167-80440f4f7a91"
-OffsetArrays = "6fe1bfb0-de20-5000-8ca7-80f57d26f881"
-Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
-Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
-StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
-Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
-Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
-
-[compat]
-Aqua = "0.8"
-Distributions = "0.25"
-DynamicHMC = "3"
-EvoTrees = "0.14.7, 0.15, 0.16"
-FFTW = "1.1"
-LogDensityProblems = "0.12, 1, 2"
-LogExpFunctions = "0.3"
-MLJBase = "0.19, 0.20, 0.21, 1"
-MLJDecisionTreeInterface = "0.3, 0.4"
-MLJIteration = "0.5, 0.6"
-MLJLIBSVMInterface = "0.2"
-MLJModels = "0.16"
-MLJXGBoostInterface = "0.3"
-OffsetArrays = "1"
-Statistics = "1.6"
-StatsBase = "0.33, 0.34"
-Tables = "1"
-julia = "1.6"