diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index add9b3d7..4bb490fc 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -92,5 +92,8 @@ jobs:
       - name: PHPUnit tests
         run: make test
 
+      - name: PHPUnit gigantic tests
+        run: "composer require --dev apis-guru/openapi-directory nexmo/api-specification; make unit_gigantic"
+
       - name: Code coverage
         run: make coverage
diff --git a/Makefile b/Makefile
index 7d9358f0..1fd7f592 100644
--- a/Makefile
+++ b/Makefile
@@ -47,7 +47,10 @@ install: composer.json package.json
 test: unit test-recursion.json test-recursion2.yaml test-recursion3_index.yaml test-empty-maps.json
 
 unit:
-	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) vendor/bin/phpunit --verbose --colors=always $(TESTCASE)
+	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) vendor/bin/phpunit --exclude-group gigantic --verbose --colors=always $(TESTCASE)
+
+unit_gigantic: # run test which requires big packages (>778 MB): apis-guru/openapi-directory, nexmo/api-specification
+	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) vendor/bin/phpunit --group gigantic --verbose --colors=always
 
 # test specific JSON files in tests/spec/data/
 # e.g. test-recursion will run validation on tests/spec/data/recursion.json
diff --git a/README.md b/README.md
index d7cd0715..71334469 100644
--- a/README.md
+++ b/README.md
@@ -320,6 +320,8 @@ You may use the docker environment for local development:
     docker-compose build
     make IN_DOCKER=1 install
     make IN_DOCKER=1 test
+    make IN_DOCKER=1 unit # run all tests except a big test (below)
+    make IN_DOCKER=1 unit_gigantic # run only a big test
     ...
 
 
diff --git a/composer.json b/composer.json
index 3dbff339..c73439ee 100644
--- a/composer.json
+++ b/composer.json
@@ -28,8 +28,6 @@
 		"phpunit/phpunit": "^6.5 || ^7.5 || ^8.5 || ^9.4",
 		"oai/openapi-specification": "3.0.3",
 		"mermade/openapi3-examples": "1.0.0",
-		"apis-guru/openapi-directory": "1.0.0",
-		"nexmo/api-specification": "1.0.0",
 		"phpstan/phpstan": "^0.12.0 || ^1.9"
 	},
 	"conflict": {
diff --git a/tests/spec/OpenApiTest.php b/tests/spec/OpenApiTest.php
index 433bd352..158908b9 100644
--- a/tests/spec/OpenApiTest.php
+++ b/tests/spec/OpenApiTest.php
@@ -184,7 +184,9 @@ public function specProvider()
     }
 
     /**
+     * This test requires 2 big packages (>778 MB): apis-guru/openapi-directory, nexmo/api-specification. So it is separated from running with other PHPUnit tests
      * @dataProvider specProvider
+     * @group gigantic
      */
     public function testSpecs($openApiFile)
     {