diff --git a/jooby/src/main/java/io/jooby/Jooby.java b/jooby/src/main/java/io/jooby/Jooby.java
index 54df7c7b52..68bbf100de 100644
--- a/jooby/src/main/java/io/jooby/Jooby.java
+++ b/jooby/src/main/java/io/jooby/Jooby.java
@@ -373,7 +373,7 @@ public String getContextPath() {
   @NonNull public Jooby install(@NonNull String path, @NonNull SneakyThrows.Supplier<Jooby> factory) {
     try {
       owner = this;
-      path(path, () -> factory.get());
+      path(path, factory::get);
       return this;
     } finally {
       owner = null;
diff --git a/jooby/src/main/java/io/jooby/internal/ServiceRegistryImpl.java b/jooby/src/main/java/io/jooby/internal/ServiceRegistryImpl.java
index 79f07cb78a..0bec8ddb94 100644
--- a/jooby/src/main/java/io/jooby/internal/ServiceRegistryImpl.java
+++ b/jooby/src/main/java/io/jooby/internal/ServiceRegistryImpl.java
@@ -17,7 +17,7 @@
 
 public class ServiceRegistryImpl implements ServiceRegistry {
 
-  private Map<ServiceKey<?>, Provider<?>> registry = new ConcurrentHashMap<>();
+  private final Map<ServiceKey<?>, Provider<?>> registry = new ConcurrentHashMap<>();
 
   @NonNull @Override
   public Set<ServiceKey<?>> keySet() {
@@ -31,7 +31,7 @@ public Set<Map.Entry<ServiceKey<?>, Provider<?>>> entrySet() {
 
   @Nullable @Override
   public <T> T getOrNull(@NonNull ServiceKey<T> key) {
-    Provider provider = registry.get(key);
+    var provider = registry.get(key);
     if (provider == null) {
       return null;
     }
diff --git a/modules/jooby-avaje-inject/src/main/java/io/jooby/avaje/inject/AvajeInjectRegistry.java b/modules/jooby-avaje-inject/src/main/java/io/jooby/avaje/inject/AvajeInjectRegistry.java
index 6123bbba70..6744c46cb7 100644
--- a/modules/jooby-avaje-inject/src/main/java/io/jooby/avaje/inject/AvajeInjectRegistry.java
+++ b/modules/jooby-avaje-inject/src/main/java/io/jooby/avaje/inject/AvajeInjectRegistry.java
@@ -1,7 +1,13 @@
+/*
+ * Jooby https://jooby.io
+ * Apache License Version 2.0 https://jooby.io/LICENSE.txt
+ * Copyright 2014 Edgar Espina
+ */
 package io.jooby.avaje.inject;
 
 import java.util.NoSuchElementException;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
 import io.avaje.inject.BeanScope;
 import io.jooby.Registry;
 import io.jooby.ServiceKey;
@@ -16,7 +22,7 @@ public AvajeInjectRegistry(BeanScope beanScope) {
   }
 
   @Override
-  public <T> T require(Class<T> type) throws RegistryException {
+  public @NonNull <T> T require(@NonNull Class<T> type) throws RegistryException {
     try {
       return beanScope.get(type);
     } catch (NoSuchElementException e) {
@@ -26,7 +32,8 @@ public <T> T require(Class<T> type) throws RegistryException {
   }
 
   @Override
-  public <T> T require(Class<T> type, String name) throws RegistryException {
+  public @NonNull <T> T require(@NonNull Class<T> type, @NonNull String name)
+      throws RegistryException {
     try {
       return beanScope.get(type, name);
     } catch (NoSuchElementException e) {
@@ -36,7 +43,11 @@ public <T> T require(Class<T> type, String name) throws RegistryException {
   }
 
   @Override
-  public <T> T require(ServiceKey<T> key) throws RegistryException {
-    return require(key.getType(), key.getName());
+  public @NonNull <T> T require(@NonNull ServiceKey<T> key) throws RegistryException {
+    if (key.getName() == null) {
+      return require(key.getType());
+    } else {
+      return require(key.getType(), key.getName());
+    }
   }
 }
diff --git a/modules/jooby-guice/src/main/java/io/jooby/guice/GuiceRegistry.java b/modules/jooby-guice/src/main/java/io/jooby/guice/GuiceRegistry.java
index 67f9b02bef..ca85be9a9c 100644
--- a/modules/jooby-guice/src/main/java/io/jooby/guice/GuiceRegistry.java
+++ b/modules/jooby-guice/src/main/java/io/jooby/guice/GuiceRegistry.java
@@ -16,7 +16,7 @@
 import io.jooby.exception.RegistryException;
 
 class GuiceRegistry implements Registry {
-  private Injector injector;
+  private final Injector injector;
 
   GuiceRegistry(Injector injector) {
     this.injector = injector;