diff --git a/test/Project.toml b/test/Project.toml
index a518221ac..25796ff10 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -27,7 +27,7 @@ MatrixAlgebraKit = {path = ".."}
 Aqua = "0.6, 0.7, 0.8"
 ChainRulesTestUtils = "1"
 EnzymeTestUtils = "0.2.5"
-ParallelTestRunner = "2"
+ParallelTestRunner = "2.9"
 Random = "1"
 StableRNGs = "1"
 Test = "1"
diff --git a/test/runtests.jl b/test/runtests.jl
index 14384eae3..8dcfeeba7 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -36,4 +36,8 @@ if filter_tests!(testsuite, args)
     end
 end
 
-runtests(MatrixAlgebraKit, args; testsuite, init_code = :(const fast_tests = $fast))
+# Enzyme test workers peak at 5-7 GB (qr, lq, orthnull on Julia 1.10), so the default
+# assumption of 2 GiB per worker oversubscribes memory on CI runners and makes them swap
+memory_per_worker = any(startswith("enzyme/") ∘ first, testsuite) ? 6 * 2^30 : 2 * 2^30
+
+runtests(MatrixAlgebraKit, args; testsuite, init_code = :(const fast_tests = $fast), memory_per_worker)