diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 0eb3948..980815a 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -16,7 +16,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: '7.2'
-          tools: phpunit:8,psalm
+          tools: phpunit:8,psalm:4
 
       - name: Setup problem matchers for PHPUnit
         run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
@@ -40,4 +40,4 @@ jobs:
 
       - name: PHPUnit
         run: phpunit --coverage-text
-        if: always()
\ No newline at end of file
+        if: always()