diff --git a/.buildkite/pipeline.yml b/.buildkite/pipeline.yml
index 97714501..6ef25dd8 100644
--- a/.buildkite/pipeline.yml
+++ b/.buildkite/pipeline.yml
@@ -1,8 +1,8 @@
 # Tests of the GPU back-ends against this version of GPUArrays. The JLArray tests on GitHub
-# Actions cover every supported Julia version, so the back-ends are only tested on the oldest
-# and newest release. Draft pull requests skip them, unless selected by name in the last commit
-# message: `[only cuda]`, `[only metal, oneapi]` or `[only tests]` for all of them. `[skip amdgpu]`
-# or `[skip tests]` does the opposite.
+# Actions cover the Julia releases in between (on pushes to main), so the back-ends are only
+# tested on the oldest and newest release. Draft pull requests skip them, unless selected by
+# name in the last commit message: `[only cuda]`, `[only metal, oneapi]` or `[only tests]` for
+# all of them. `[skip amdgpu]` or `[skip tests]` does the opposite.
 steps:
   # Julia 1.10 doesn't support [sources] in Project.toml,
   # so we need to manually dev CUDA.jl's workspace packages.
diff --git a/.github/workflows/Test.yml b/.github/workflows/Test.yml
index aa691a2a..fe2d8021 100644
--- a/.github/workflows/Test.yml
+++ b/.github/workflows/Test.yml
@@ -21,7 +21,9 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: ['1.10', '1.11', '1.12', '1.13', 'nightly']
+        # pull requests only test the oldest and newest supported release
+        version: ${{ fromJSON(github.event_name == 'pull_request' && '["1.10", "1.13"]' ||
+                              '["1.10", "1.11", "1.12", "1.13", "nightly"]') }}
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
       - uses: actions/checkout@v6
@@ -65,7 +67,7 @@ jobs:
       - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@v3
         with:
-          version: '1.12'
+          version: '1.13'
           show-versioninfo: true
       - uses: julia-actions/cache@v3
       - name: Run tests