diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f30332e..9d0a3da 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -12,10 +12,10 @@ jobs:
     # Set timeout to prevent overcharging
     timeout-minutes: 20
     steps:
-      - uses: maxim-lobanov/setup-xcode@v1.2.3
+      - uses: maxim-lobanov/setup-xcode@v1
         with:
-          xcode-version: 12.4
+          xcode-version: latest
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: Test
-        run: swift test --parallel
+        run: swift test
diff --git a/Sources/Biodag/Biodag.swift b/Sources/Biodag/Biodag.swift
index f03a430..cb3038b 100644
--- a/Sources/Biodag/Biodag.swift
+++ b/Sources/Biodag/Biodag.swift
@@ -15,36 +15,40 @@ import Foundation
 
 /// A dependency collection that provides resolutions for object instances.
 final public class DependencyResolver {
+    private let moduleArray: [Module]
     /// Stored object instance factories.
     private var modules = [String: Module]()
     private var instances = [String: Any]()
 
     /// Construct dependency resolutions.
     public init(@ModuleBuilder _ modules: () -> [Module]) {
-        modules().forEach { add(module: $0) }
+        self.moduleArray = modules()
     }
 
     /// Construct dependency resolution.
     public init(@ModuleBuilder _ module: () -> Module) {
-        add(module: module())
+        self.moduleArray = [module()]
     }
 
     /// Assigns the current container to the composition root.
     public func build() {
-        Self.root = self
+        for module in moduleArray {
+            Self.root.add(module: module)
+        }
     }
 
-    fileprivate init() {}
-    deinit { modules.removeAll() }
+    fileprivate init() {
+        self.moduleArray = []
+    }
 }
 
 private extension DependencyResolver {
     /// Composition root container of dependencies.
-    static var root = DependencyResolver()
+    static let root = DependencyResolver()
 
     /// Registers a specific type and its instantiating factory.
     func add(module: Module) {
-        modules[module.name] = module
+        self.modules[module.name] = module
     }
 
     /// Resolves through inference and returns an instance of the given type from the current default container.
diff --git a/Tests/BiodagTests/BiodagTests.swift b/Tests/BiodagTests/BiodagTests.swift
index e3d36c8..61c2165 100644
--- a/Tests/BiodagTests/BiodagTests.swift
+++ b/Tests/BiodagTests/BiodagTests.swift
@@ -82,6 +82,24 @@ extension DependencyTests {
         // The singletons are the same instance
         XCTAssertTrue(singletonModule === helperSingleton)
     }
+
+    func testAddingDependencies() {
+        struct Added { }
+        struct NotAdded { }
+
+        let newResolver = DependencyResolver({
+            Module { Added() as Added }
+        })
+        newResolver.build()
+
+
+        @Inject var widgetModule: WidgetModuleType
+        @Inject var added: Added
+        @Inject var notAdded: NotAdded
+
+        XCTAssertNotNil(widgetModule)
+        XCTAssertNotNil(added)
+    }
 }
 
 // MARK: - Subtypes