diff --git a/src/CommandBus/SymfonyParameterResolver.php b/src/CommandBus/SymfonyParameterResolver.php
index 2fa9c41f..12d79643 100644
--- a/src/CommandBus/SymfonyParameterResolver.php
+++ b/src/CommandBus/SymfonyParameterResolver.php
@@ -5,9 +5,14 @@
 namespace Patchlevel\EventSourcingBundle\CommandBus;
 
 use Patchlevel\EventSourcing\CommandBus\Handler\ParameterResolver;
+use Patchlevel\EventSourcing\CommandBus\Handler\ServiceNotResolvable;
 use Psr\Container\ContainerInterface;
 use ReflectionMethod;
+use Symfony\Component\TypeInfo\Type\ObjectType;
+use Symfony\Component\TypeInfo\TypeResolver\TypeResolver;
 
+use function is_a;
+use function sprintf;
 use function strtolower;
 
 final class SymfonyParameterResolver implements ParameterResolver
@@ -22,14 +27,39 @@ public function resolve(ReflectionMethod $method, object $command): iterable
     {
         $prefix = strtolower($method->getName()) . '.';
 
-        foreach ($method->getParameters() as $index => $parameter) {
-            if ($index === 0) {
-                yield $command; // first parameter is always the command
+        foreach ($method->getParameters() as $parameter) {
+            $serviceId = $prefix . $parameter->getName();
+
+            $this->container->has($serviceId);
+
+            if ($this->container->has($serviceId)) {
+                yield $this->container->get($serviceId);
+
+                continue;
+            }
+
+            $reflectionType = $parameter->getType();
+
+            if ($reflectionType === null) {
+                ServiceNotResolvable::missingType($method->getDeclaringClass()->getName(), $parameter->getName());
+            }
+
+            $type = TypeResolver::create()->resolve($reflectionType);
+
+            if ($type instanceof ObjectType && is_a($command, $type->getClassName(), true)) {
+                yield $command;
 
                 continue;
             }
 
-            yield $this->container->get($prefix . $parameter->getName());
+            throw new ServiceNotResolvable(
+                sprintf(
+                    'Missing service for parameter "%s" in "%s::%s"',
+                    $parameter->getName(),
+                    $method->getDeclaringClass()->getName(),
+                    $method->getName(),
+                ),
+            );
         }
     }
 }
diff --git a/src/DependencyInjection/HandlerServiceLocatorCompilerPass.php b/src/DependencyInjection/HandlerServiceLocatorCompilerPass.php
index 87eb52a6..6de89f44 100644
--- a/src/DependencyInjection/HandlerServiceLocatorCompilerPass.php
+++ b/src/DependencyInjection/HandlerServiceLocatorCompilerPass.php
@@ -56,11 +56,7 @@ private function services(ReflectionMethod $method, ContainerInterface $containe
         $services = [];
         $prefix = strtolower($method->getName()) . '.';
 
-        foreach ($method->getParameters() as $index => $parameter) {
-            if ($index === 0) {
-                continue; // skip first parameter (command)
-            }
-
+        foreach ($method->getParameters() as $parameter) {
             $key = $prefix . $parameter->getName();
 
             $attributes = $parameter->getAttributes(Inject::class);
@@ -102,6 +98,10 @@ private function services(ReflectionMethod $method, ContainerInterface $containe
                 continue;
             }
 
+            if (!$container->has($type->getClassName())) {
+                continue;
+            }
+
             $services[$key] = new Reference($type->getClassName());
         }