diff --git a/tests/acceptance/acceptance/ContainerService.feature b/tests/acceptance/acceptance/ContainerService.feature
index eca7710..03e58f5 100644
--- a/tests/acceptance/acceptance/ContainerService.feature
+++ b/tests/acceptance/acceptance/ContainerService.feature
@@ -4,23 +4,26 @@ Feature: Container service
 
   Background:
     Given I have Symfony plugin enabled
-
-  Scenario: Asserting psalm recognizes return type of service got via 'ContainerInterface::get()'
-    Given I have the following code
+    And I have the following code preamble
       """
       <?php
+
+      use \Symfony\Component\DependencyInjection\ContainerInterface;
+
       class SomeService
       {
         public function do(): void {}
       }
+      """
 
-      class SomeController
+  Scenario: Asserting psalm recognizes return type of service got via 'ContainerInterface::get()'
+    Given I have the following code
+      """
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get(SomeService::class)->do();
+          $container->get(SomeService::class)->do();
         }
       }
       """
@@ -30,19 +33,11 @@ Feature: Container service
   Scenario: Asserting psalm recognizes return type of service got via 'ContainerInterface::get()'.
     Given I have the following code
       """
-      <?php
-      class SomeService
-      {
-        public function do(): void {}
-      }
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get(SomeService::class)->nosuchmethod();
+          $container->get(SomeService::class)->nosuchmethod();
         }
       }
       """
@@ -55,18 +50,16 @@ Feature: Container service
   Scenario: Container get(self::class) should not crash
     Given I have the following code
       """
-      <?php
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index()
+        public function index(ContainerInterface $container): void
         {
-          $this->container->get(self::class)->index();
+          $container->get(self::class)->index();
         }
       }
       """
     When I run Psalm
     Then I see these errors
-      | Type              | Message                                                                  |
-      | MissingReturnType | Method SomeController::index does not have a return type, expecting void |
+      | Type            | Message                                                                          |
+      | MixedMethodCall | Cannot determine the type of the object on the left hand side of this expression |
+    And I see no other errors
diff --git a/tests/acceptance/acceptance/ContainerXml.feature b/tests/acceptance/acceptance/ContainerXml.feature
index 8c4f8ab..6cb8b9c 100644
--- a/tests/acceptance/acceptance/ContainerXml.feature
+++ b/tests/acceptance/acceptance/ContainerXml.feature
@@ -7,19 +7,21 @@ Feature: Container XML config
       """
       <containerXml>../../tests/acceptance/container.xml</containerXml>
       """
+    And I have the following code preamble
+      """
+      <?php
+
+      use \Symfony\Component\DependencyInjection\ContainerInterface;
+      """
 
   Scenario: Asserting psalm recognizes return type of service got via 'ContainerInterface::get() using service ID'
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): bool
+        public function __invoke(ContainerInterface $container): bool
         {
-          return $this->container->get('service_container')->has('lorem');
+          return $container->get('service_container')->has('lorem');
         }
       }
       """
@@ -29,15 +31,11 @@ Feature: Container XML config
   Scenario: Psalm emits when service ID not found in container'
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get('not_a_service')->has('lorem');
+          $container->get('not_a_service')->has('lorem');
         }
       }
       """
@@ -49,18 +47,12 @@ Feature: Container XML config
   Scenario: Using service both via alias and class const
     Given I have the following code
       """
-      <?php
-
-      use Symfony\Component\HttpKernel\HttpKernelInterface;
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get('http_kernel');
-          $this->container->get(HttpKernelInterface::class);
+          $container->get('http_kernel');
+          $container->get(HttpKernelInterface::class);
         }
       }
       """
@@ -70,15 +62,11 @@ Feature: Container XML config
   Scenario: Using private service
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get('private_service');
+          $container->get('private_service');
         }
       }
       """
diff --git a/tests/acceptance/acceptance/HeaderBag.feature b/tests/acceptance/acceptance/HeaderBag.feature
index 157278c..ae1a753 100644
--- a/tests/acceptance/acceptance/HeaderBag.feature
+++ b/tests/acceptance/acceptance/HeaderBag.feature
@@ -2,7 +2,7 @@
 Feature: Header get
 
   Background:
-    Given I have issue handler "UnusedFunctionCall" suppressed
+    Given I have issue handler "UnusedVariable" suppressed
     And I have Symfony plugin enabled
     And I have the following code preamble
       """
@@ -11,24 +11,23 @@ Feature: Header get
       use Symfony\Component\HttpFoundation\Request;
       """
 
-  Scenario: HeaderBag get method return type should return `?string` (unless third argument is provided for < Sf4.4)
+  Scenario: HeaderBag get method return type should return `?string`
     Given I have the following code
       """
       class App
       {
         public function index(Request $request): void
         {
-          $string = $request->headers->get('nullable_string');
-          if (!$string) {
-            return;
-          }
-
-          trim($string);
+          /** @psalm-trace $nullableString */
+          $nullableString = $request->headers->get('nullable_string');
         }
       }
       """
     When I run Psalm
-    Then I see no errors
+    Then I see these errors
+      | Type  | Message                        |
+      | Trace | $nullableString: null\|string  |
+    And I see no other errors
 
   Scenario: HeaderBag get method return type should return `string` if default value is provided with string
     Given I have the following code
@@ -37,11 +36,13 @@ Feature: Header get
       {
         public function index(Request $request): void
         {
+          /** @psalm-trace $string */
           $string = $request->headers->get('string', 'string');
-
-          trim($string);
         }
       }
       """
     When I run Psalm
-    Then I see no errors
+    Then I see these errors
+      | Type  | Message         |
+      | Trace | $string: string |
+    And I see no other errors
diff --git a/tests/acceptance/acceptance/NamingConventions.feature b/tests/acceptance/acceptance/NamingConventions.feature
index a376170..928149f 100644
--- a/tests/acceptance/acceptance/NamingConventions.feature
+++ b/tests/acceptance/acceptance/NamingConventions.feature
@@ -7,19 +7,22 @@ Feature: Naming conventions
       """
       <containerXml>../../tests/acceptance/container.xml</containerXml>
       """
+    And I have the following code preamble
+      """
+      <?php
+
+      use \Symfony\Component\DependencyInjection\ContainerInterface;
+      use \Symfony\Component\HttpKernel\HttpKernelInterface;
+      """
 
   Scenario: There is no service naming convention violation, so no complaint.
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): bool
+        public function __invoke(ContainerInterface $container): bool
         {
-          return $this->container->get('service_container')->has('lorem');
+          return $container->get('service_container')->has('lorem');
         }
       }
       """
@@ -29,15 +32,11 @@ Feature: Naming conventions
   Scenario: Detects service naming convention violation
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get('wronglyNamedService');
+          $container->get('wronglyNamedService');
         }
       }
       """
@@ -50,17 +49,11 @@ Feature: Naming conventions
   Scenario: No service naming convention violation when using FQCNs
     Given I have the following code
       """
-      <?php
-
-      use Symfony\Component\HttpKernel\HttpKernelInterface;
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function __invoke(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->get(HttpKernelInterface::class);
+          $container->get(HttpKernelInterface::class);
         }
       }
       """
@@ -70,15 +63,11 @@ Feature: Naming conventions
   Scenario: No naming convention violation for parameter
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->getParameter('kernel.cache_dir');
+          $container->getParameter('kernel.cache_dir');
         }
       }
       """
@@ -88,15 +77,11 @@ Feature: Naming conventions
   Scenario: Detects parameter naming convention violation
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function index(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->getParameter('wronglyNamedParameter');
+          $container->getParameter('wronglyNamedParameter');
         }
       }
       """
@@ -109,15 +94,11 @@ Feature: Naming conventions
   Scenario: No parameter naming convention violation when using environment variables
     Given I have the following code
       """
-      <?php
-
-      class SomeController
+      class App
       {
-        use \Symfony\Component\DependencyInjection\ContainerAwareTrait;
-
-        public function __invoke(): void
+        public function __invoke(ContainerInterface $container): void
         {
-          $this->container->getParameter('env(SOME_ENV_VAR)');
+          $container->getParameter('env(SOME_ENV_VAR)');
         }
       }
       """