diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b2fdb191..c5b819ef 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -38,10 +38,9 @@ jobs:
       - name: "Install dependencies"
         run: "composer install --no-interaction --no-progress --no-suggest"
 
-      - name: "Update PHPUnit"
-        if: matrix.php-version == '7.4' || matrix.php-version == '8.0'
-        run: "composer require --dev phpunit/phpunit:'^9.5' --update-with-dependencies"
-
+      - name: "Downgrade PHPUnit"
+        if: matrix.php-version == '7.1' || matrix.php-version == '7.2' || matrix.php-version == '7.3'
+        run: "composer require --dev phpunit/phpunit:^7.5.20 --update-with-dependencies"
 
       - name: "Lint"
         run: "make lint"
@@ -108,9 +107,9 @@ jobs:
         if: ${{ matrix.dependencies == 'highest' }}
         run: "composer update --no-interaction --no-progress --no-suggest"
 
-      - name: "Update PHPUnit"
-        if: matrix.php-version == '7.4' || matrix.php-version == '8.0'
-        run: "composer require --dev phpunit/phpunit:'^9.5' --update-with-dependencies"
+      - name: "Downgrade PHPUnit"
+        if: matrix.php-version == '7.1' || matrix.php-version == '7.2' || matrix.php-version == '7.3'
+        run: "composer require --dev phpunit/phpunit:^7.5.20 --update-with-dependencies"
 
       - name: "Tests"
         run: "make tests"
@@ -144,9 +143,9 @@ jobs:
       - name: "Install dependencies"
         run: "composer update --no-interaction --no-progress --no-suggest"
 
-      - name: "Update PHPUnit"
-        if: matrix.php-version == '7.4' || matrix.php-version == '8.0'
-        run: "composer require --dev phpunit/phpunit:'^9.5' --update-with-dependencies"
+      - name: "Downgrade PHPUnit"
+        if: matrix.php-version == '7.1' || matrix.php-version == '7.2' || matrix.php-version == '7.3'
+        run: "composer require --dev phpunit/phpunit:^7.5.20 --update-with-dependencies"
 
       - name: "PHPStan"
         run: "make phpstan"
diff --git a/composer.json b/composer.json
index 2f08f4d0..3719f1d9 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
 		"phpstan/extension-installer": "^1.0",
 		"phpstan/phpstan": "^0.12.60",
 		"phpstan/phpstan-strict-rules": "^0.12.5",
-		"phpunit/phpunit": "^7.5.20",
+		"phpunit/phpunit": "^9.5",
 		"symfony/process": "^5.2"
 	},
 	"config": {