diff --git a/src/Illuminate/Session/SessionManager.php b/src/Illuminate/Session/SessionManager.php
index 578fc2107ab2..0b176ef6d01a 100755
--- a/src/Illuminate/Session/SessionManager.php
+++ b/src/Illuminate/Session/SessionManager.php
@@ -269,7 +269,7 @@ public function getSessionConfig()
     /**
      * Get the default session driver name.
      *
-     * @return string
+     * @return string|null
      */
     public function getDefaultDriver()
     {
diff --git a/src/Illuminate/Support/Manager.php b/src/Illuminate/Support/Manager.php
index ebd95c85a03c..5a1052e490d0 100755
--- a/src/Illuminate/Support/Manager.php
+++ b/src/Illuminate/Support/Manager.php
@@ -50,7 +50,7 @@ public function __construct(Container $container)
     /**
      * Get the default driver name.
      *
-     * @return string
+     * @return string|null
      */
     abstract public function getDefaultDriver();
 
diff --git a/tests/Integration/Support/Fixtures/NullableManager.php b/tests/Integration/Support/Fixtures/NullableManager.php
index c1e9e84ce0c2..3a8b741412a9 100644
--- a/tests/Integration/Support/Fixtures/NullableManager.php
+++ b/tests/Integration/Support/Fixtures/NullableManager.php
@@ -9,7 +9,7 @@ class NullableManager extends Manager
     /**
      * Get the default driver name.
      *
-     * @return string
+     * @return string|null
      */
     public function getDefaultDriver()
     {