diff --git a/README.md b/README.md
index 5ca5b3a..105c15e 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 ClassFinder
 ===========
 
-A dead simple utility to identify classes in a given namespace.
+A dead simple utility to identify classes, traits and interfaces in a given namespace.
 
 This package is an improved implementation of an [answer on Stack Overflow](https://stackoverflow.com/a/40229665/3000068)
 and provides additional features with less configuration required.
@@ -50,7 +50,14 @@ Examples
 
 require_once __DIR__ . '/vendor/autoload.php';
 
+// Will default to ClassFinder::ALLOW_CLASSES
 $classes = ClassFinder::getClassesInNamespace('TestApp1\Foo');
+$classes = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::ALLOW_CLASSES);
+$interfaces = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::ALLOW_INTERFACES);
+$traits = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::ALLOW_TRAITS);
+
+// You can combine any of the flags
+$interfacesTraits = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::ALLOW_TRAITS | ClassFinder::ALLOW_INTERFACES);
 
 /**
  * array(
@@ -60,6 +67,27 @@ $classes = ClassFinder::getClassesInNamespace('TestApp1\Foo');
  * )
  */
 var_dump($classes);
+/**
+ * array(
+ *   'TestApp1\Foo\BarInterface',
+ *   'TestApp1\Foo\FooInterface'
+ * )
+ */
+var_dump($interfaces);
+/**
+ * array(
+ *   'TestApp1\Foo\BazTrait',
+ * )
+ */
+var_dump($traits);
+/**
+ * array(
+ *   'TestApp1\Foo\BarInterface',
+ *   'TestApp1\Foo\FooInterface',
+ *   'TestApp1\Foo\BazTrait',
+ * )
+ */
+var_dump($interfacesTraits);
 ```
 
 **Recursive Mode** *(in v0.3-beta)*
@@ -69,7 +97,15 @@ var_dump($classes);
 
 require_once __DIR__ . '/vendor/autoload.php';
 
+// As before, will default to ClassFinder::ALLOW_CLASSES
 $classes = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::RECURSIVE_MODE);
+$classes = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::RECURSIVE_MODE | ClassFinder::ALLOW_CLASSES);
+$interfaces = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::RECURSIVE_MODE | ClassFinder::ALLOW_INTERFACES);
+$traits = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::RECURSIVE_MODE | ClassFinder::ALLOW_TRAITS);
+
+
+// You can combine any of the flags
+$classesTraits = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::RECURSIVE_MODE | ClassFinder::ALLOW_CLASSS | ClassFinder::ALLOW_TRAITS);
 
 /**
  * array(
@@ -85,6 +121,11 @@ $classes = ClassFinder::getClassesInNamespace('TestApp1\Foo', ClassFinder::RECUR
  * )
  */
 var_dump($classes);
+
+// You get the idea :)
+var_dump($interfaces);
+var_dump($traits);
+var_dump($classesTraits);
 ```
  
 Documentation
diff --git a/src/ClassFinder.php b/src/ClassFinder.php
index c20ddc3..f6bc331 100644
--- a/src/ClassFinder.php
+++ b/src/ClassFinder.php
@@ -13,6 +13,11 @@ class ClassFinder
 {
     const STANDARD_MODE = 1;
     const RECURSIVE_MODE = 2;
+    const ALLOW_CLASSES = 4;
+    const ALLOW_INTERFACES = 8;
+    const ALLOW_TRAITS = 16;
+
+    const MODE_MASK = 3;
 
     /** @var AppConfig */
     private static $config;
@@ -71,6 +76,10 @@ class ClassFinder
      */
     public static function getClassesInNamespace($namespace, $options = self::STANDARD_MODE)
     {
+        if (!($options & (self::ALLOW_INTERFACES | self::ALLOW_TRAITS))) {
+            // Default to classes
+            $options |= self::ALLOW_CLASSES;
+        }
         self::initialize();
 
         $findersWithNamespace = self::findersWithNamespace($namespace);
diff --git a/src/Classmap/ClassmapEntryFactory.php b/src/Classmap/ClassmapEntryFactory.php
index d1f2539..71ffb7e 100644
--- a/src/Classmap/ClassmapEntryFactory.php
+++ b/src/Classmap/ClassmapEntryFactory.php
@@ -3,6 +3,7 @@
 namespace HaydenPierce\ClassFinder\Classmap;
 
 use HaydenPierce\ClassFinder\AppConfig;
+use HaydenPierce\ClassFinder\ClassFinder;
 
 class ClassmapEntryFactory
 {
@@ -17,12 +18,18 @@ class ClassmapEntryFactory
     /**
      * @return ClassmapEntry[]
      */
-    public function getClassmapEntries()
+    public function getClassmapEntries($allowAdditional = ClassFinder::ALLOW_INTERFACES | ClassFinder::ALLOW_TRAITS)
     {
         // Composer will compile user declared mappings to autoload_classmap.php. So no additional work is needed
         // to fetch user provided entries.
         $classmap = require($this->appConfig->getAppRoot() . 'vendor/composer/autoload_classmap.php');
 
+        $classmap = array_filter($classmap, function ($potentialClass) use ($allowAdditional) {
+            return ($allowAdditional & ClassFinder::ALLOW_CLASSES && class_exists($potentialClass))
+                || ($allowAdditional & ClassFinder::ALLOW_INTERFACES && interface_exists($potentialClass))
+                || ($allowAdditional & ClassFinder::ALLOW_TRAITS && trait_exists($potentialClass));
+        }, ARRAY_FILTER_USE_KEY);
+
         // if classmap has no entries return empty array
         if(count($classmap) == 0) {
             return array();
diff --git a/src/Classmap/ClassmapFinder.php b/src/Classmap/ClassmapFinder.php
index f5875a4..4a16087 100644
--- a/src/Classmap/ClassmapFinder.php
+++ b/src/Classmap/ClassmapFinder.php
@@ -38,7 +38,7 @@ class ClassmapFinder implements FinderInterface
      */
     public function findClasses($namespace, $options)
     {
-        $classmapEntries = $this->factory->getClassmapEntries();
+        $classmapEntries = $this->factory->getClassmapEntries($options);
 
         $matchingEntries = array_filter($classmapEntries, function(ClassmapEntry $entry) use ($namespace, $options) {
             return $entry->matches($namespace, $options);
diff --git a/src/Files/FilesEntry.php b/src/Files/FilesEntry.php
index c1a27b5..06a8b5c 100644
--- a/src/Files/FilesEntry.php
+++ b/src/Files/FilesEntry.php
@@ -2,6 +2,8 @@
 
 namespace HaydenPierce\ClassFinder\Files;
 
+use HaydenPierce\ClassFinder\ClassFinder;
+
 class FilesEntry
 {
     /** @var string */
@@ -38,14 +40,14 @@ class FilesEntry
     }
 
     /**
-     * Gets a list of classes that belong to the given namespace.
-     *
+     * Gets a list of classes that belong to the given namespace
      * @param string $namespace
+     * @param int    $options
      * @return string[]
      */
-    public function getClasses($namespace)
+    public function getClasses($namespace, $options)
     {
-        $classes = $this->getClassesInFile();
+        $classes = $this->getClassesInFile($options);
 
         return array_values(array_filter($classes, function($class) use ($namespace) {
             $classNameFragments = explode('\\', $class);
@@ -58,6 +60,19 @@ class FilesEntry
         }));
     }
 
+    /**
+     * Execute PHP code and return retuend value
+     *
+     * @param string $script
+     * @return mixed
+     */
+    private function execReturn($script)
+    {
+        exec($this->php . " -r \"$script\"", $output);
+        $classes = 'return ' . implode('', $output) . ';';
+        return eval($classes);
+    }
+
     /**
      * Dynamically execute files and check for defined classes.
      *
@@ -68,24 +83,35 @@ class FilesEntry
      *
      * @return array
      */
-    private function getClassesInFile()
+    private function getClassesInFile($options = ClassFinder::ALLOW_INTERFACES | ClassFinder::ALLOW_TRAITS)
     {
-        // get_declared_classes() returns a bunch of classes that are built into PHP. So we need a control here.
-        $script = "var_export(get_declared_classes());";
-        exec($this->php . " -r \"$script\"", $output);
-        $classes = 'return ' . implode('', $output) . ';';
-        $initialClasses = eval($classes);
-
-        // clear the exec() buffer.
-        unset($output);
+        // get_declared_*() returns a bunch of classes|interfaces|traits that are built into PHP. So we need a control here.
+        list($initialInterfaces, 
+            $initialClasses, 
+            $initialTraits
+        ) = $this->execReturn("var_export(array(get_declared_interfaces(), get_declared_classes(), get_declared_traits()));");
 
         // This brings in the new classes. so $classes here will include the PHP defaults and the newly defined classes
-        $script = "require_once '{$this->file}'; var_export(get_declared_classes());";
-        exec($this->php . ' -r "' . $script . '"', $output);
-        $classes = 'return ' . implode('', $output) . ';';
-        $allClasses = eval($classes);
+        list($allInterfaces,
+            $allClasses,
+            $allTraits
+        ) = $this->execReturn("require_once '{$this->file}'; var_export(array(get_declared_interfaces(), get_declared_classes(), get_declared_traits()));");
 
-        return array_diff($allClasses, $initialClasses);
+        $interfaces = array_diff($allInterfaces, $initialInterfaces);
+        $classes = array_diff($allClasses, $initialClasses);
+        $traits = array_diff($allTraits, $initialTraits);
+
+        $final = array();
+        if ($options & ClassFinder::ALLOW_CLASSES) {
+            $final = $classes;
+        }
+        if ($options & ClassFinder::ALLOW_INTERFACES) {
+            $final = array_merge($final, $interfaces);
+        }
+        if ($options & ClassFinder::ALLOW_TRAITS) {
+            $final = array_merge($final, $traits);
+        }
+        return $final;
     }
 
     /**
diff --git a/src/Files/FilesFinder.php b/src/Files/FilesFinder.php
index 0370ed2..389c300 100644
--- a/src/Files/FilesFinder.php
+++ b/src/Files/FilesFinder.php
@@ -52,8 +52,8 @@ class FilesFinder implements FinderInterface
     {
         $filesEntries = $this->factory->getFilesEntries();
 
-        return array_reduce($filesEntries, function($carry, FilesEntry $entry) use ($namespace){
-            return array_merge($carry, $entry->getClasses($namespace));
+        return array_reduce($filesEntries, function($carry, FilesEntry $entry) use ($namespace, $options){
+            return array_merge($carry, $entry->getClasses($namespace, $options));
         }, array());
     }
 }
diff --git a/src/PSR4/PSR4Namespace.php b/src/PSR4/PSR4Namespace.php
index 2b2bd9b..6d00a71 100644
--- a/src/PSR4/PSR4Namespace.php
+++ b/src/PSR4/PSR4Namespace.php
@@ -168,6 +168,9 @@ class PSR4Namespace
      */
     public function findClasses($namespace, $options = ClassFinder::STANDARD_MODE)
     {
+        $allowAdditional = $options & ~ClassFinder::MODE_MASK;
+        $options &= ClassFinder::MODE_MASK;
+
         $relativePath = substr($namespace, strlen($this->namespace));
 
         $self = $this;
@@ -194,24 +197,27 @@ class PSR4Namespace
         }, $potentialClassFiles);
 
         if ($options == ClassFinder::RECURSIVE_MODE) {
-            return $this->getClassesFromListRecursively($namespace);
+            return $this->getClassesFromListRecursively($namespace, $allowAdditional);
         } else {
-            return array_filter($potentialClasses, function($potentialClass) {
+            return array_filter($potentialClasses, function($potentialClass) use ($allowAdditional) {
                 if (function_exists($potentialClass)) {
                     // For some reason calling class_exists() on a namespace'd function raises a Fatal Error (tested PHP 7.0.8)
                     // Example: DeepCopy\deep_copy
                     return false;
                 } else {
-                    return class_exists($potentialClass);
+                    return ($allowAdditional & ClassFinder::ALLOW_CLASSES && class_exists($potentialClass))
+                        || ($allowAdditional & ClassFinder::ALLOW_INTERFACES && interface_exists($potentialClass))
+                        || ($allowAdditional & ClassFinder::ALLOW_TRAITS && trait_exists($potentialClass));
                 }
             });
         }
     }
 
     /**
+     * @param int $allowAdditional
      * @return string[]
      */
-    private function getDirectClassesOnly()
+    private function getDirectClassesOnly($allowAdditional)
     {
         $self = $this;
         $directories = array_reduce($this->directories, function($carry, $directory) use ($self){
@@ -237,27 +243,30 @@ class PSR4Namespace
             return $selfNamespace . str_replace('.php', '', $file);
         }, $potentialClassFiles);
 
-        return array_filter($potentialClasses, function($potentialClass) {
+        return array_filter($potentialClasses, function($potentialClass) use ($allowAdditional) {
             if (function_exists($potentialClass)) {
                 // For some reason calling class_exists() on a namespace'd function raises a Fatal Error (tested PHP 7.0.8)
                 // Example: DeepCopy\deep_copy
                 return false;
             } else {
-                return class_exists($potentialClass);
+                return ($allowAdditional & ClassFinder::ALLOW_CLASSES && class_exists($potentialClass))
+                    || ($allowAdditional & ClassFinder::ALLOW_INTERFACES && interface_exists($potentialClass))
+                    || ($allowAdditional & ClassFinder::ALLOW_TRAITS && trait_exists($potentialClass));
             }
         });
     }
 
     /**
      * @param string $namespace
+     * @param $allowAdditional
      * @return string[]
      */
-    public function getClassesFromListRecursively($namespace)
+    public function getClassesFromListRecursively($namespace, $allowAdditional)
     {
-        $initialClasses = strpos( $this->namespace, $namespace) !== false ? $this->getDirectClassesOnly() : array();
+        $initialClasses = strpos( $this->namespace, $namespace) !== false ? $this->getDirectClassesOnly($allowAdditional) : array();
 
-        return array_reduce($this->getDirectSubnamespaces(), function($carry, PSR4Namespace $subNamespace) use ($namespace) {
-            return array_merge($carry, $subNamespace->getClassesFromListRecursively($namespace));
+        return array_reduce($this->getDirectSubnamespaces(), function($carry, PSR4Namespace $subNamespace) use ($namespace, $allowAdditional) {
+            return array_merge($carry, $subNamespace->getClassesFromListRecursively($namespace, $allowAdditional));
         }, $initialClasses);
     }
 
diff --git a/test/unit/Files/FilesEntryTest.php b/test/unit/Files/FilesEntryTest.php
index ae02748..20a221a 100644
--- a/test/unit/Files/FilesEntryTest.php
+++ b/test/unit/Files/FilesEntryTest.php
@@ -46,7 +46,7 @@ EOL
 
         $files = new FilesEntry($tmpFilename, $this->findPHP());
 
-        $classes = $files->getClasses($namespace);
+        $classes = $files->getClasses($namespace, 0);
 
         $this->assertEquals($expected, $classes, 'FilesEntry should be able to determine the classes defined in a given file.');
     }