diff --git a/specs/namespace/creation-for-whitelist.php b/specs/namespace/creation-for-whitelist.php
new file mode 100644
index 00000000..5a0c216c
--- /dev/null
+++ b/specs/namespace/creation-for-whitelist.php
@@ -0,0 +1,300 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the humbug/php-scoper package.
+ *
+ * Copyright (c) 2017 Théo FIDRY <theo.fidry@gmail.com>,
+ *                    Pádraic Brady <padraic.brady@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+return [
+    'meta' => [
+        'title' => 'Namespace declaration creation for whitelisted classes which belong to the global namespace.',
+        // Default values. If not specified will be the one used
+        'prefix' => 'Humbug',
+        'whitelist' => [],
+    ],
+
+    'Single class should receive namespace' => <<<'PHP'
+<?php
+
+class AppKernel
+{
+}
+
+----
+<?php
+
+namespace Humbug;
+
+class AppKernel
+{
+}
+
+PHP
+    ,
+
+    'Single abstract class should receive namespace.' => <<<'PHP'
+<?php
+
+abstract class AppKernel
+{
+}
+
+----
+<?php
+
+namespace Humbug;
+
+abstract class AppKernel
+{
+}
+
+PHP
+    ,
+
+    'Final class declaration should be prefixed.' => <<<'PHP'
+<?php
+
+final class AppKernel {}
+----
+<?php
+
+namespace Humbug;
+
+final class AppKernel
+{
+}
+
+PHP
+    ,
+
+    'Interfaces can be whitelisted too.' => <<<'PHP'
+<?php
+
+interface AppKernel
+{
+}
+
+----
+<?php
+
+namespace Humbug;
+
+interface AppKernel
+{
+}
+
+PHP
+    ,
+
+    'Multiple classes should all receive namespace in the same file.' => <<<'PHP'
+<?php
+
+class AppKernalOther2
+{
+}
+
+class AppKernel
+{
+}
+
+class AppKernalOther
+{
+}
+
+----
+<?php
+
+namespace {
+    class AppKernalOther2
+    {
+    }
+}
+namespace Humbug {
+    class AppKernel
+    {
+    }
+}
+namespace {
+    class AppKernalOther
+    {
+    }
+}
+
+PHP
+    ,
+
+    'Multiple interfaces should all receive namespace in the same file.' => <<<'PHP'
+<?php
+
+interface AppKernel
+{
+}
+
+class AppKernalOther
+{
+}
+
+interface SomeInterface
+{
+}
+
+----
+<?php
+
+namespace Humbug {
+    interface AppKernel
+    {
+    }
+}
+namespace {
+    class AppKernalOther
+    {
+    }
+}
+namespace {
+    interface SomeInterface
+    {
+    }
+}
+
+PHP
+    ,
+
+    'Defines should be wrapped in namespace alongside whitelisted class.' => <<<'PHP'
+<?php
+
+define("MY_DEFINE", "value");
+
+class AppKernel
+{
+}
+
+----
+<?php
+
+namespace {
+    \define("MY_DEFINE", "value");
+}
+namespace Humbug {
+    class AppKernel
+    {
+    }
+}
+
+PHP
+    ,
+
+    'Make sure anonymous classes are not wrapped.' => <<<'PHP'
+<?php
+
+new class {};
+
+class AppKernel
+{
+}
+
+----
+<?php
+
+namespace {
+    new class
+    {
+    };
+}
+namespace Humbug {
+    class AppKernel
+    {
+    }
+}
+
+PHP
+    ,
+
+    'Make sure traits are not prefixed.' => <<<'PHP'
+<?php
+
+trait AppKernel
+{
+}
+
+----
+<?php
+
+trait AppKernel
+{
+}
+
+PHP
+    ,
+
+    'Make sure traits are not prefixed next to whitelisted class.' => <<<'PHP'
+<?php
+
+trait SomeTrait
+{
+}
+
+class AppKernel
+{
+}
+
+----
+<?php
+
+namespace {
+    trait SomeTrait
+    {
+    }
+}
+namespace Humbug {
+    class AppKernel
+    {
+    }
+}
+
+PHP
+    ,
+
+    'Traits in different namespace.' => <<<'PHP'
+<?php
+
+namespace Foo {
+    trait SomeTrait{}
+}
+
+namespace {
+    class AppKernel{}
+}
+
+namespace {
+    class Bla{}
+}
+
+----
+<?php
+
+namespace Humbug\Foo {
+    trait SomeTrait
+    {
+    }
+}
+namespace Humbug {
+    class AppKernel
+    {
+    }
+}
+namespace {
+    class Bla
+    {
+    }
+}
+
+PHP
+];
diff --git a/src/NodeVisitor/NamespaceStmtPrefixer.php b/src/NodeVisitor/NamespaceStmtPrefixer.php
index 747f31de..56a1779c 100644
--- a/src/NodeVisitor/NamespaceStmtPrefixer.php
+++ b/src/NodeVisitor/NamespaceStmtPrefixer.php
@@ -17,6 +17,8 @@
 use Humbug\PhpScoper\NodeVisitor\Collection\NamespaceStmtCollection;
 use PhpParser\Node;
 use PhpParser\Node\Name;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\Interface_;
 use PhpParser\Node\Stmt\Namespace_;
 use PhpParser\NodeVisitorAbstract;
 use function Humbug\PhpScoper\clone_node;
@@ -38,15 +40,25 @@ final class NamespaceStmtPrefixer extends NodeVisitorAbstract
 {
     private $prefix;
     private $namespaceStatements;
+    private $hasWhitelistedNode;
+    private $globalWhitelister;
+
+    public function __construct(
+        string $prefix,
+        NamespaceStmtCollection $namespaceStatements,
+        callable $globalWhitelister
+    ) {
+        $this->prefix = $prefix;
+        $this->namespaceStatements = $namespaceStatements;
+        $this->globalWhitelister = $globalWhitelister;
+    }
 
     /**
-     * @param string                  $prefix
-     * @param NamespaceStmtCollection $namespaceStatements
+     * @inheritdoc
      */
-    public function __construct(string $prefix, NamespaceStmtCollection $namespaceStatements)
+    public function beforeTraverse(array $nodes)
     {
-        $this->prefix = $prefix;
-        $this->namespaceStatements = $namespaceStatements;
+        $this->hasWhitelistedNode = $this->hasWhitelistedNode($nodes);
     }
 
     /**
@@ -59,6 +71,18 @@ public function enterNode(Node $node): Node
             : $node;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function leaveNode(Node $node)
+    {
+        return (
+            !$this->hasWhitelistedNode
+            || $node instanceof Namespace_
+            || AppendParentNode::hasParent($node)
+        ) ? $node : $this->wrapNamespace($node);
+    }
+
     private function prefixNamespaceStmt(Namespace_ $namespace): Node
     {
         $originalNamespace = $namespace;
@@ -74,8 +98,62 @@ private function prefixNamespaceStmt(Namespace_ $namespace): Node
         return $namespace;
     }
 
+    private function wrapNamespace(Node $node): Node
+    {
+        if ($this->isWhitelistedNode($node)) {
+            return new Namespace_(new Node\Name($this->prefix), [$node]);
+        }
+
+        // Anything else needs to be wrapped with global namespace.
+        return new Namespace_(null, [$node]);
+    }
+
+    /**
+     * @param Node[] $nodes
+     *
+     * @return bool
+     */
+    private function hasWhitelistedNode(array $nodes): bool
+    {
+        foreach ($nodes as $node) {
+            if ($this->isWhitelistedNode($node)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private function isWhitelistedNode(Node $node)
+    {
+        if (($node instanceof Class_ || $node instanceof Interface_)
+            && ($this->globalWhitelister)($node->name)
+        ) {
+            return true;
+        }
+
+        // Check nodes in the global namespaces.
+        if ($node instanceof Namespace_ && null === $node->name) {
+            foreach ($node->stmts as $statement) {
+                if ($this->isWhitelistedNode($statement)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
     private function shouldPrefixStmt(Namespace_ $namespace): bool
     {
-        return null !== $namespace->name && $this->prefix !== $namespace->name->getFirst();
+        if (null !== $namespace->name && $this->prefix !== $namespace->name->getFirst()) {
+            return true;
+        }
+
+        if (null === $namespace->name && $this->hasWhitelistedNode([$namespace])) {
+            return true;
+        }
+
+        return false;
     }
 }
diff --git a/src/Scoper/TraverserFactory.php b/src/Scoper/TraverserFactory.php
index 23e7f3d9..233cfe31 100644
--- a/src/Scoper/TraverserFactory.php
+++ b/src/Scoper/TraverserFactory.php
@@ -56,7 +56,7 @@ public function create(string $prefix, array $whitelist, callable $globalWhiteli
 
         $traverser->addVisitor(new NodeVisitor\AppendParentNode());
 
-        $traverser->addVisitor(new NodeVisitor\NamespaceStmtPrefixer($prefix, $namespaceStatements));
+        $traverser->addVisitor(new NodeVisitor\NamespaceStmtPrefixer($prefix, $namespaceStatements, $globalWhitelister));
 
         $traverser->addVisitor(new NodeVisitor\UseStmt\UseStmtCollector($namespaceStatements, $useStatements));
         $traverser->addVisitor(new NodeVisitor\UseStmt\UseStmtPrefixer($prefix, $whitelist, $globalWhitelister));