diff --git a/.github/workflows/mutation.yml b/.github/workflows/mutation.yml
index e19b6b0..ee97f6a 100644
--- a/.github/workflows/mutation.yml
+++ b/.github/workflows/mutation.yml
@@ -28,13 +28,8 @@ jobs:
 
     strategy:
       matrix:
-        os:
-          - ubuntu-latest
-
-        php:
-          - '8.0'
-          - '8.1'
-          - '8.2'
+        os: [ 'ubuntu-latest' ]
+        php: [ '8.3' ]
 
     steps:
       - name: Checkout
diff --git a/Makefile b/Makefile
index 88e5536..0e0af5d 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ connect-cluster:	## Connect to Redis cluster
 mutation-test:		## Run mutation tests. Params: {{ v=8.1 }}. Default latest PHP 8.1
 	PHP_VERSION=$(filter-out $@,$(v)) docker-compose -f tests/docker/docker-compose.yml build --pull cache-redis-php
 	make create-cluster
-	PHP_VERSION=$(filter-out $@,$(v)) docker-compose -f tests/docker/docker-compose.yml run cache-redis-php php -dpcov.enabled=1 -dpcov.directory=. vendor/bin/roave-infection-static-analysis-plugin -j2 --ignore-msi-with-no-mutations --only-covered
+	PHP_VERSION=$(filter-out $@,$(v)) docker-compose -f tests/docker/docker-compose.yml run cache-redis-php php -dpcov.enabled=1 -dpcov.directory=. vendor/bin/roave-infection-static-analysis-plugin --threads=2 --ignore-msi-with-no-mutations --only-covered
 	make down
 
 coverage:		## Run code coverage. Params: {{ v=8.1 }}. Default latest PHP 8.1