diff --git a/.docker/php7.4/Dockerfile b/.docker/php7.4/Dockerfile
index 62885d73..918ba660 100644
--- a/.docker/php7.4/Dockerfile
+++ b/.docker/php7.4/Dockerfile
@@ -10,6 +10,8 @@ RUN apt-get update \
      libzip-dev \
     && docker-php-ext-install zip \
     && docker-php-ext-install opcache \
+    && pecl install -o ds \
+    && echo "extension=ds.so" > /usr/local/etc/php/conf.d/ds.ini \
     && rm -r /var/lib/apt/lists/*
 
 RUN pecl install xdebug \
diff --git a/.github/workflows/validate-code.yml b/.github/workflows/validate-code.yml
index 8677ea4b..6d614fe7 100644
--- a/.github/workflows/validate-code.yml
+++ b/.github/workflows/validate-code.yml
@@ -24,7 +24,8 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          tools: composer
+          tools: composer, pecl
+          extensions: ds
 
       - name: Validate composer.json and composer.lock
         run: composer validate
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e01d4ea3..71f586df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## [Unreleased]
+### Fixed
+- Fixed an issue where `ext-ds` classes where not recognized as used
+
 ## [0.7.3] - 2020-05-19
 ### Added
 - Added workflow to verify integrity of build `phar` file
diff --git a/Makefile b/Makefile
index 2d906927..8b57d8cb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,35 +1,31 @@
+CONTAINER=composer-unused-7.4
+
 up:
 	if [ "$(shell docker-machine status default)" != 'Running' ]; then \
 		docker-machine start default; \
 	fi;
-	eval ${docker-machine env}
+	eval ${shell docker-machine env}
 	docker-compose up -d
 
 down:
 	docker-compose down
 
-7.4:
-	eval $(export COMPOSER_UNUSED_PHP_VERSION=composer-unused-7.4)
-
-7.3:
-	eval $(export COMPOSER_UNUSED_PHP_VERSION=composer-unused-7.3)
-
 install:
-	docker exec -it $(COMPOSER_UNUSED_PHP_VERSION) composer install
+	docker exec -it $(CONTAINER) composer install
 
 update:
-	docker exec -it $(COMPOSER_UNUSED_PHP_VERSION) composer update
+	docker exec -it $(CONTAINER) composer update
 
 check: csfix cs phpunit analyse
 
 phpunit:
-	docker exec -it $(COMPOSER_UNUSED_PHP_VERSION) vendor/bin/phpunit
+	docker exec -it $(CONTAINER) vendor/bin/phpunit
 
 analyse:
-	docker exec -it $(COMPOSER_UNUSED_PHP_VERSION) vendor/bin/phpstan analyse
+	docker exec -it $(CONTAINER) vendor/bin/phpstan analyse
 
 cs:
-	docker exec -it $(COMPOSER_UNUSED_PHP_VERSION) vendor/bin/phpcs
+	docker exec -it $(CONTAINER) vendor/bin/phpcs
 
 csfix:
-	docker exec -it $(COMPOSER_UNUSED_PHP_VERSION) vendor/bin/phpcbf
+	docker exec -it $(CONTAINER) vendor/bin/phpcbf
diff --git a/src/Parser/PHP/Strategy/PhpExtensionStrategy.php b/src/Parser/PHP/Strategy/PhpExtensionStrategy.php
index f301cfdb..238ddb1a 100644
--- a/src/Parser/PHP/Strategy/PhpExtensionStrategy.php
+++ b/src/Parser/PHP/Strategy/PhpExtensionStrategy.php
@@ -104,8 +104,9 @@ public function extractNamespaces(Node $node): array
     private function getNameFromNode(Node $node): string
     {
         if ($node instanceof Node\Name\FullyQualified) {
-            return $node->parts[0];
+            return implode('\\', $node->parts);
         }
+
         if ($node instanceof Node\Stmt\UseUse) {
             return $node->name->parts[0];
         }
diff --git a/tests/Integration/Parser/PHP/NodeVisitorTest.php b/tests/Integration/Parser/PHP/NodeVisitorTest.php
index 6b465d8d..38b36d80 100644
--- a/tests/Integration/Parser/PHP/NodeVisitorTest.php
+++ b/tests/Integration/Parser/PHP/NodeVisitorTest.php
@@ -156,6 +156,11 @@ public function itShouldParseUsagesDataProvider(): array
                 'inputFile'              => ASSET_DIR . '/TestFiles/PhpExtensionStrategy/ClassWithCore.php',
                 'strategy'               => new PhpExtensionStrategy(['Core'], new NullLogger())
             ],
+            'PhpExtensionParseStrategyShouldReturnQualifiedNamespace---11'        => [
+                'expectedUsedNamespaces' => ['ext-ds'],
+                'inputFile'              => ASSET_DIR . '/TestFiles/PhpExtensionStrategy/ClassWithDs.php',
+                'strategy'               => new PhpExtensionStrategy(['ds'], new NullLogger())
+            ],
         ];
     }
 
diff --git a/tests/assets/TestFiles/PhpExtensionStrategy/ClassWithDs.php b/tests/assets/TestFiles/PhpExtensionStrategy/ClassWithDs.php
new file mode 100644
index 00000000..ebd72d83
--- /dev/null
+++ b/tests/assets/TestFiles/PhpExtensionStrategy/ClassWithDs.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TestFile {
+    class ClassWithDs
+    {
+        public function foo()
+        {
+            $map = new \Ds\Map();
+        }
+    }
+}