diff --git a/source/poodinis/registration.d b/source/poodinis/registration.d
index f2ea281..fdebf2b 100644
--- a/source/poodinis/registration.d
+++ b/source/poodinis/registration.d
@@ -85,3 +85,8 @@ class ExistingInstanceScope : RegistrationScope {
 		return instance;
 	}
 }
+
+public Registration existingInstance(Registration registration, Object instance) {
+	registration.registationScope = new ExistingInstanceScope(instance);
+	return registration;
+}
diff --git a/test/poodinis/containertest.d b/test/poodinis/containertest.d
index c5db07a..1bb92c1 100644
--- a/test/poodinis/containertest.d
+++ b/test/poodinis/containertest.d
@@ -100,7 +100,7 @@ version(unittest) {
 		container.register!(TestClass)().singleInstance();
 		auto instance1 = container.resolve!(TestClass);
 		auto instance2 = container.resolve!(TestClass);
-		assert(instance1 is instance2);
+		assert(instance1 is instance2, "Resolved instance from single instance scope is not the each time it is resolved");
 	}
 	
 	// Test resolve new instance for type
@@ -109,7 +109,16 @@ version(unittest) {
 		container.register!(TestClass)().newInstance();
 		auto instance1 = container.resolve!(TestClass);
 		auto instance2 = container.resolve!(TestClass);
-		assert(instance1 !is instance2);
+		assert(instance1 !is instance2, "Resolved instance from new instance scope is the same each time it is resolved");
+	}
+	
+	// Test resolve existing instance for type
+	unittest {
+		auto container = new Container();
+		auto expectedInstance = new TestClass();
+		container.register!(TestClass)().existingInstance(expectedInstance);
+		auto actualInstance = container.resolve!(TestClass);
+		assert(expectedInstance is actualInstance, "Resolved instance from existing instance scope is not the same as the registered instance");
 	}
 	
 }
\ No newline at end of file
diff --git a/test/poodinis/registrationtest.d b/test/poodinis/registrationtest.d
index 7bb3ad1..e94c0bd 100644
--- a/test/poodinis/registrationtest.d
+++ b/test/poodinis/registrationtest.d
@@ -49,7 +49,7 @@ version(unittest) {
 		auto instance2 = registration.getInstance();
 		assert(instance1 !is instance2, "Registration with new instance scope did not return a different instance");
 		assert(registration is chainedRegistration, "Registration returned by scope setting is not the same as the registration being set");
-	} 
+	}
 	
 	// Test getting instance from existing instance scope
 	unittest {
@@ -60,4 +60,14 @@ version(unittest) {
 		assert(expectedInstance is actualInstance, "Registration with existing instance did not return given instance");
 	}
 	
+	// Test set existing instance scope using scope setter
+	unittest {
+		Registration registration = new Registration(null, null);
+		auto expectedInstance = new TestType();
+		auto chainedRegistration = registration.existingInstance(expectedInstance);
+		auto actualInstance = registration.getInstance();
+		assert(expectedInstance is expectedInstance, "Registration with existing instance scope did not return the same instance");
+		assert(registration is chainedRegistration, "Registration returned by scope setting is not the same as the registration being set");
+	}
+	
 }
\ No newline at end of file