diff --git a/Sources/Resolve.swift b/Sources/Resolve.swift
index 3f0c435..11d2e50 100644
--- a/Sources/Resolve.swift
+++ b/Sources/Resolve.swift
@@ -253,7 +253,7 @@ extension DependencyContainer {
     
     //if no definition registered for exact type try to find type-forwarding definition that can resolve the type
     //that will actually happen only when resolving optionals
-    if definitions.filter({ $0.0.type == key.type }).isEmpty {
+    guard definitions.contains(where: { $0.0.type == key.type }) else {
       return typeForwardingDefinition(forKey: key)
     }
     return nil
diff --git a/Tests/DipTests/AutoInjectionTests.swift b/Tests/DipTests/AutoInjectionTests.swift
index ef9f065..cd9e9e4 100644
--- a/Tests/DipTests/AutoInjectionTests.swift
+++ b/Tests/DipTests/AutoInjectionTests.swift
@@ -51,12 +51,12 @@ private class ClientImp: Client {
   
   @Injected(didInject: { _ in
     AutoInjectionTests.serverDidInjectCalled = true
-  }) var server: Server
+  }) var server: Server?
   
   @Injected(required: false) var _optionalProperty: AnyObject?
-  
-  @Injected(tag: "tagged") var taggedServer: Server
-  @Injected(tag: nil) var nilTaggedServer: Server
+    
+  @Injected(tag: "tagged") var taggedServer: Server?
+  @Injected(tag: nil) var nilTaggedServer: Server?
   
   var anotherServer: Server!
 }