diff --git a/pkgbuilds/flea/PKGBUILD b/pkgbuilds/flea/PKGBUILD
index 2808c60c..a8cd3fdc 100644
--- a/pkgbuilds/flea/PKGBUILD
+++ b/pkgbuilds/flea/PKGBUILD
@@ -2,7 +2,7 @@
 
 pkgname=flea
 pkgver=0.3.1
-pkgrel=1
+pkgrel=2
 pkgdesc='Fast, keyboard-first file manager for Omarchy'
 arch=('x86_64' 'aarch64')
 url='https://github.com/thisisgm/flea'
@@ -64,7 +64,13 @@ build() {
 check() {
   cd "$pkgname-$pkgver"
 
-  export CARGO_TARGET_DIR=target
+  # Upstream's release profile uses fat LTO, whose final link runs on one
+  # thread. build() keeps it for the shipped binary; the test harness is a
+  # throwaway second compile, so build it in parallel in its own target
+  # directory.
+  export CARGO_TARGET_DIR=target-check
+  export CARGO_PROFILE_RELEASE_LTO=thin
+  export CARGO_PROFILE_RELEASE_CODEGEN_UNITS=16
 
   local -a test_args=()
   if ! /usr/bin/prlimit --cpu=30 --as=1073741824 \
diff --git a/pkgbuilds/strata/PKGBUILD b/pkgbuilds/strata/PKGBUILD
index 11cbbd10..4b6a14b9 100644
--- a/pkgbuilds/strata/PKGBUILD
+++ b/pkgbuilds/strata/PKGBUILD
@@ -1,6 +1,6 @@
 pkgname=strata
 pkgver=0.19.0
-pkgrel=1
+pkgrel=2
 pkgdesc='Fast, keyboard-first file manager for modern Linux desktops'
 arch=('x86_64' 'aarch64')
 url='https://github.com/lgse/strata'
@@ -69,7 +69,16 @@ build() {
 check() {
   cd "$pkgname-$pkgver"
 
-  export CARGO_TARGET_DIR=target
+  # Upstream's release profile is fat LTO with one codegen unit, which
+  # compiles the final crate on a single thread. That is the right trade
+  # for the binary users run, and build() keeps it. The test harness is a
+  # second compile of the same crate under the same profile, thrown away
+  # afterwards; build it in parallel, in its own target directory so the
+  # shipped binary is untouched. Measured on the x86_64 builder: 708 s
+  # serial, 223 s with thin LTO and 16 units.
+  export CARGO_TARGET_DIR=target-check
+  export CARGO_PROFILE_RELEASE_LTO=thin
+  export CARGO_PROFILE_RELEASE_CODEGEN_UNITS=16
   export STRATA_BUILD_COMMIT
   STRATA_BUILD_COMMIT=$(<.build-commit)
   export STRATA_RELEASE_TAG="v$pkgver"